Communication and Network

Modulation

It is the transmission of a signal by using it to vary a carrier wave, changing the carrier's amplitude, frequency or phase. Besides that, it is the process of conveying a message signal. Modulation is the process of converting digital signal to analog signal. Modem is the device that is used for the modulation process.

Demodulation

It is a process of retrieving data or message conveyed from the modulator. Besides that, it interprets and changes the signal delivered by the modulator. Demodulation process converts analog signal to digital signal. Modem, the same device used for the modulation process is also used in this process.

Bandwidth

It is a measurement of data that can be carried from one point to another in a given time period. Bandwidth is usually measured in bits (of data) per second (bps). For example, to transfer texts or documents, a slow bandwidth is used and to transfer audio or video files, a wider bandwidth is needed. There are three types of bandwidth which are voiceband (used for dial-up service), medium band (leased lines) and broadband (used for DSL and high capacity transmission).

TCP/IP



Short for transmission control protocol/internet protocol, it is the standard protocol or rules for the Internet. It allows different kinds of computers on different networks to communicate. Therefore, connecting them by a "universal" language. The essential features of TCP/IP is are identification and packetization. Identification is to identify sending and receiving devices whereas packetization reformats the information for transmission across the Internet. For identification, the internet uses IP address to deliver email and locate websites and the domain name server (DNS) converts the text-based adress to IP address. The function is the similar to a postal address. Packetization transmits information through interconnected networks. Before a message is sent, it is reformatted into packets and each packet is sent separately through the Internet. These packets are then reassemble into the correct order when received.


Node

It is a connection point for networks. It can be any device connected to a network. For example, a computer, printer, a data storage device or an active electronic device that is attached to a network. Besides that, it is capable of sending, receiving or forwarding information over a communications channel.

Client

It is a node that requests and uses resources available from other nodes. Basically, a client is a user’s microcomputer. Besides that, a client is capable of obtaining information and applications from a server. Clients make "requests" through a network or networks, and receive "responses" from servers.

Server

It is a a node that shares resources with other nodes. Servers provide essential services across a network through the Internet. There are many servers and each of them are assigned to a specific task. Dedicated servers that are assigned to a specific tasks are  web servers, print servers, and database servers.

Network Operating Systems

It is an operating system that has special functions for connecting computers and devices into a local-area network (LAN). NOS controls and coordinates activities of all computer and devices on the network. Such activities include electronic communication and the sharing of information and resources. Examples of networking operating systems are Novell Netware, Artisoft's LANtastic, Microsoft Windows Server, and Windows NT.

Network Administrator

A computer specialist who manages a communications network in an organization. Responsibilities include implementing new networks, maintaining network operations efficiently and network security. Besides that, installing new hardware and applications, monitoring software upgrades, enforcing licensing agreements, developing a storage management program and providing for routine backups.

Secondary Storage

Disk Caching 

It is a mechanism for improving the time it takes to read from or write to a hard disk. A disk cache can also be a specified portion of RAM. Nowadays, it can be found on hard disk. It also holds data that has recently been read.

File Compression

It helps to reduce  the overall number of bits and bytes in a file so it can be transmitted faster over slower Internet connections, or take up less space on a disk. Most computers have the same information listed over and over again. Therefore, instead of listing the information over and over again, file compression programs lists that information once and then refers back to it whenever it appears in the original program. Compressed files are called "archives" and may contain more than one file. WinZip, WinRar, and 7-Zip are popular types of file archival that all offer data compression.

File Decompression

When compressed files are sent and received by the recipient, the files must be decompressed to be used. When a file archive, such as a .zip or .rar is decompressed it will expand and extract a series of files or folders from that single file. Decompressing files are also known as unzipping or extracting files.

Internet Hard Drive

Its works the same as the hard drive only it has the advantage of users being able to access their files online. Users may upload music, videos, documents or any other files online. There is no limited storage capacity compared to a hard drive. Internet hard drive makes it easier for users as they are able to log in any computer that has an internet connection to access their hard drive.

Optical Disk Drive

It is a is a disk drive that uses laser light or electromagnetic waves near the light spectrum as part of the process of reading or writing data to or from optical discs. It retrieves and stores data on optical discs like CDs, DVDs and Blu-ray discs. Most optical disk drives can play and record a large number of disc formats.

Solid-state Storage

It is a nonvolatile and removable storage medium that employs integrated circuits rather than magnetic or optical media. It also has a nonvolatile memory. Data is stored and retrieved electronically directly from these devices. Examples of solid-stage storages are flash memory cards and memory sticks. This type of storage is compatible with digital cameras, camcorders and computers. 

Input and Output

Ergonomic Keyboard

This keyboard is designed to relieve some of the stress caused by typing due to the usage of fingers, hands and the wrists. It helps as it instills comfort to the users hands and wrists when they type. The "split hands" design is the central feature of the keyboard as it provides a more natural positioning for the hands to be more widely separated when typing. In conclusion, ergonomic keyboards provides a more natural position for typing and helps to reduce muscle stress on fingers, hands and wrists. This type of keyboard is also highly recommended by therapists and health care professionals.

Inkjet Printer

It is a type of printer that works by spraying ionized ink at a sheet of paper. Magnetized plates in the ink's path direct the ink onto the paper in the desired shapes. It is capable of producing high-quality prints. A typical inkjet printer offers a resolution of 300 dots per inch. Inkjet printers are also slower compared to laser printers and requires a special type of ink. The price of this type of printer is also cheaper compared to laser printers.

Laser Printer

It is a type of printer that works by using a focused beam or light to transfer texts and images onto paper. The printer works by having the paper pass through the printer then the laser beam fires at the surface of a cylindrical drum. This drum has an electrical charge (typically positive), that is reversed in areas where the laser beam hits it. By reversing the charge in certain areas of the drum, the laser beam can print patterns (such as text and pictures) onto the cylindrical drum. The pattern is then coated with toners. Laser printers has less image smearing problems because they do not use ink. Laser printers typically have a resolution of 600 dpi (dots per inch) or higher.

Magnetic-ink Character Recognition

Known also as MICR, it is primarily used by the bank industry. The technology allows computers to read information (such as account numbers) off printed documents and can be easily read by humans. MICR characters are printed in special typefaces with a magnetic ink or toner, usually containing iron oxide. The use of magnetic printing allows the characters to be read reliably even if they have been overprinted or obscured by other marks.

Optical-character Recognition

Abbreviated OCR, an OCR system enables you to take a book or a magazine article, feed it directly into an electronic computer file, and then edit the file using a word processor. All OCR systems include an optical scanner for reading text, and sophisticated software for analyzing images. OCR enables users to harness the power of computers to access printed documents.

Optical-mark Recognition

It electronically extracts intended data from marked fields, such as checkboxes and fill-infields, on printed forms. This technology is useful for applications in which large numbers of hand-filled forms need to be processed quickly and with great accuracy, such as surveys, reply cards and questionnaires. It is mostly used in schools for multiple-choice tests. The device scans the document and reads the data from the marked fields. The error rate for OMR technology is less than 1%.

System Unit

RAM

Short for Random Access Memory is a type of computer data storage than can be accessed randomly. Any byte of memory can be accessed without touching the preceding bytes. It is the most common type of memory found in computers and devices such as printers. RAM is also known as the main memory.

Cache Memory

It is a RAM that a computer microprocessor can access at a quick rate of time compared to a regular RAM. As the microprocessor processes data, it looks first in the cache memory and if data is found there, it does not have to do the more time consuming reading of data from large memory. RAM itself can be considered as a cache of memory for a hard disk storage because of all RAM's contents come from the hard disk when a computer is switched on and load the operating system as well as applications and data.

ROM

Also known as Read-Only Memory, it is a memory on which data has been previously prerecorded. When data has been written onto a ROM chip, it cannot be removed and can only be read. Compared to a RAM, contents that is being kept by ROM is still retained when a computer is switched off.

Flash Memory

It is a solid state chip that maintains stored information without an external power source, also known as electronically erasable programmable read-only memory. It does not need any power source to retain data. It is often used in portable devices such as MP3 players, smart phones and digital cameras. It can also be found in computers as well.

Graphic Card

It is a device in a computer that contains graphics processing unit designed to help process and display images especially 3D graphics. Graphic cards contain their own memory to take off the strain of the RAM system. Graphic cards are also known as video cards.

Sound Card

Also known as audio card, enables a computer to manipulate and output sounds. It enables sounds to be output from the computer through speakers connected through the board, record sound input recorded from the microphone connected to the computer and manipulate sound stored in a disk. Sound cards uses FM synthesis and wavetable synthesis to translate digital data into analog sounds.

Network Interface Card

This device allows computers to connect through a local area network. It is known as a network adapter. Networked computers communicate with each other using a given protocol or agreed-upon language for transmitting data packets between the different machines. The network interface cards works as the liaison for the machine to send and receive data on the local area network.

Plug and Play

Plug and Play enables users to plug in a device into a computer and have the computer to recognize that the device is there. The user does not have to tell the computer that a device has been plugged in. Instead, the Plug and Play automatically detects the plugged device by itself.

Serial Port

It is a port that is used for serial communication. Information is transferred in or out at one bit at a time. A serial port can be used for any types of devices such as printers and modems. 

Parallel Port

It is a parallel interface that connects external devices such as a printer. The parallel port uses a 25-pin connector to connect printers, computers and other devices that needs high bandwidth. It is also known as a centronics port.

Universal Serial Bus Port

Or as users call it, USB port is a standard cable connection interface on personal computers and consumer electronics. It allows electronics to be connected through a cable to a computer. Computer networking equipments such as USB network adapters, USB modems and cellular modems for internet access and USB printers that are used to be shared on the same network are plugged into the USB port.

Firewire Port

It is a form of serial port that uses firewire technology and enables data to be transferred rapidly from an electric device to another. The transfer rate of a firewire port can reach up to 400 Mbps. The data transferred is fast and gives excellent quality of results.

Ethernet Port

It is a port for connecting the device to a wired network. It is normally located at the back of the CPU. Ethernet ports are usually connected to its internal ethernet network adapter. Besides that, ethernet ports can be found on routers and consumer electronics such as game controls, digital video recorders and new televisions. 

High Definition Multimedia Interface

Long for HDMI, is an audio and video interface that connects through a single cable. HDMI can connect  a DVD player, A/V receiver, video game consoles and etc. to an output device such as television and projectors. HDMI supports standard, enhanced, high definition video and multi channel digital audio.

Basic and Specialized Software Application

GRAPHICAL USER INTERFACE

Also known as GUI, it is a type of user interface in a graphical form for users to interact with programs. It allows the user to select from menus & icons using a mouse or keystroke commands. GUI is used by most modern operating systems.

WORD PROCESSOR

It is an application that enables users to compose, edit, format & print documents. Besides that, documents can also be modified or opened on any other computer using the same word processor application. An example of a notable word processor application is Microsoft Word.

SPREADSHEET

It is a document of data that is stored in a table of values arranged in horizontal rows & vertical columns. Rows are labelled using numbers while columns are labelled using alphabets. Individual row/columns are called cells. Examples of cells are C5, E20 & etc. Information stored in a spreadsheet is more structured. The row/column structure allows data to be analyzed using calculation & formulas.

DBMS

DBMS is short for Database Management System. It is a database program that creates & maintains the use of a database. It manages incoming data, organizes it & provides ways for data to be modified or extracted by users or other programs.

UTILITY SUITES

It is an all-in-one package for maintenance & clean up for the computer. The package includes antivirus as well. Besides that, the package helps to protect the computer from threats online.  Furthermore, there will be notifications of updates to ensure the computer is always maintained & up-to-date.

WEB AUTHORING

It is a category of software that enables users to create a website in a desktop publishing format. The software will generate the required HTML coding for the layout of the web page based on the user's design. The user can toggle back & forth between the graphical design & HTML code to make changes to the web page. An example of a notable web authoring program is Adobe Dreamweaver.

AUDIO EDITING SOFTWARE

It is a software that allows users to edit & manipulate digital audio. Besides that, users can create, restore, record & convert the files as well. This software plays a huge role for those who are involved in the digital audio field.

BITMAP IMAGE

It is a type of graphic made up of pixels in a grid. Each pixel of the image is called a "bit" & contains colour information for the image. Bitmap graphic formats have a fixed resolution. Meaning, resizing the image would result in distortion & jagged edges on the image. It is simply known as .BMP & other common formats are GIF, JPG or JPEG, TIFF, PNG, PICT & PCX.

DESKTOP PUBLISHING PROGRAM

It allows users to produce high-quality printed documents. The program allows users to different typefaces, specify various margins and justifications, and embed illustrations and graphs directly into the text. Certain desktop publishing softwares also enables users to create illustrations. An important feature of the program is it enables users to see on the display screen how the document will appear when printed. This particular feature is known as WYSIWYG (What You See Is What You Get).

HTML EDITOR

It is a software program that inserts HTML code as HTML file is being created. It helps users who are encoding HTML by cataloging & catching errors. It often displays tags & contents in colours so they appear strikingly for easy reference. 

MULTIMEDIA

The name itself is an integration of multiple forms of media. Graphics, text, audio, video & etc. are examples of multimedia. Combined audio & visual components are considered multimedia.

VECTOR IMAGE

It is an image made up of paths, points, curves & angles unlike BMPs, JPEGs & GIFs images. A path can create a simple drawing or a diagram. Vector images are ideal for logos. A common software program used for this is Adobe Illustrator.

The Internet, The Web and Electronic Commerce

URL

URL, short form for Uniform Resource Locater is the global address of documents & other resources online. It is also known as an internet adress. A URL contains access protocol (http), the domain name (www.blogger.com) & the path to a file or resource residing on that server (.com, .net, .zip, .xml).

HTML

HTML is the short for HyperText Markup Language, the language used to create text & multimedia documents on the World Wide Web. HTML uses a variety of tags & attributes to create a document or a web page. A correct structure for an HTML document starts with <HTML><HEAD>(enter here what document is about)<BODY> and ends with </BODY></HTML>.

Javascript

Javascript is a scripting language used by web authors to design interactive sites. It is used in Web developments to automatically change a formatted date on a Web page, cause a link-to page to appear in a popup window & cause text or graphic image to change or animate during a mouse rollover. JavaScript code can be imbedded in HTML pages and interpreted by the Web browser.

Applets

A small application that performs one specific task under the control of a larger application, typically a Web browser. It is designed to be executed from within another application & cannot be executed directly from the operating system. Applets are small in files size, highly secure & ideal for small Internet applications accessible from a browser. 

Blogs

It is an online journal usually maintained by an individual used to document their events in life or state their opinions intended for general public consumption. Blogs are usually updated on a regular basis. A typical blog may include text, images, videos, links & other forms of media. This blog itself is an example of a blog.

Wikis

Wiki is derived from a Hawaiian phrase, "wiki wiki" which means super-fast. An example of Wiki is Wikipedia. It allows users to add, update & edit content on the site by using their own Web browsers. Wikis are powered by Wiki software & are often used to create collaborative works.

FTP

FTP is short for File Transfer Protocol, which allow files to be exchanged between computers on the Internet. To transfer files using FTP, a program called a "client" is needed. It creates a connection to a remote computer running FTP "server" software. After a connection is established, the client may choose to send a receive a copy of the file. To connect to an FTP server, a client requires the username & password set by the administrator of the server. FTP is mostly used on the Internet to upload & download files.

Plug-in

It is an add-on for a program to add extra features or functionality to it. Plug-ins are a convenient way to expand the capabilities of a program. Examples of plug-ins are shown on the picture above.

Filters

It is a program that is designed to accept a certain type of data as an input, transforms it & outputs the transformed data. An example is shown on the picture above. The names are sorted in an alphabetical order because it has filtered the unsorted order & has outputted the sorted names in an alphabetical order.

Internet Security Suite

It contains a suite of utilities to maintain the security of the computer. Utilities such as spam blocker, antivirus, personal firewall & pop-up blocker are included. These are to protect the computer against virus or threats online that can corrupt your computer.