Explanation

• DNS stands for Domain Name System.
• It translates website names (like google.com) into IP addresses.
• It works like the “phone book of the internet.”
• Without DNS, users would need to remember numeric IP addresses.
• DNS was introduced in 1983.

Last verified on 26-05-2026

Explanation

• A standard CD-ROM is an optical storage device used for data storage.
• It is commonly used to store software, audio, and files.
• The typical storage capacity of a normal CD-ROM is 680 MB.
• It is now mostly replaced by DVDs and USB drives.

Last verified on 17-05-2026

Explanation

An email address consists of two parts: 

1. Username or ID (the name or ID chosen by the user)
2. Domain name (the name of the organization or service provider).

Format: Username@Domainname.com

Example: john.doe@example.com

Additional information:

• Email, short for Electronic Mail, has its roots in the early 1960s.
• The first email was sent in 1971 by Ray Tomlinson.
• He also introduced the "@" symbol to separate the username from the hostname.

Last verified on 19-04-2026

Explanation

• DOS stands for Disk Operating System.
• It is an early type of computer operating system used to manage files and programs.
• It works through text-based commands (command line).
• A famous example is MS-DOS used in early PCs. 
• Dennis Ritchie is the father of MS-DOS.
• It was developed in 1982.

Last verified on 19-04-2026

Explanation

The size of information in the computer is measured in: 

• 1024 kilobytes (KB) is equal to 1 megabyte (MB).
• One Megabyte (MB) = 1024 Kilobytes (KB
• One Gigabyte (GB) =  1024 Megabytes MB
• One Terabyte (TB)= 1024 gigabytes (GB).

Explanation

Explanation

• Optical Fiber Systems are utilized in Telecommunication Systems to transmit data as light signals through thin glass or plastic fibers.
• It enabling high-speed internet, voice, and data communications over long distances.

Last verified on 03-04-2026

Explanation

• Ctrl + T: Opens a new tab
• Ctrl + N: Opens a new window
• Ctrl + Shift + W: Closes the current window and all tabs
• Ctrl + Q: Closes the current window
• Alt + Right arrow: Opens the next page from your browsing history in the current tab
• Ctrl + F4: Closes the current tab
• Alt + F4: Closes the active window
• Alt + Space then n: Minimizes the current window

Last update 0n 21-07-2026 by NA

Explanation

Explanation

• LED (Light Emitting Diode) is a semiconductor device that emits light when electric current passes through it.
• It is widely used in lighting, displays, electronic indicators, and screens.

Additional information:

• Energy efficiency: Up to 90% more efficient than traditional bulbs
  First discovery: H. J. Round – 1907
  Early research: Oleg Losev – 1927
  Practical LED development: James R. Biard – 1961
  First commercial production: October 1962 (Nick Holonyak)

Last verified on 12-03-2026