1. Extensions are called top-level domains.

2. File extensions are used so that the computer's operating system or OS can recognize the file type.

3. A file extension primarily refers to a suffix added to the end of a computer file (an object containing information, data or commands) to define the file type.

1. Internet means-

The Internet is a worldwide network of computers. The Internet consists of many local, regional, national and international networks. It is an international network of computers that interconnects millions of enterprises, government agencies, educational institutions individuals, etc. There is no denying the fact that the Internet has created a revolution in the way we live our lives. It has changed the way we communicate, do business and receive information, as well as our entertainment.

2. Network meaning is-

- A network is a group of computers that are interconnected through various devices so that they can communicate with each other.

Networks can be classified in many ways. One way to classify networks is based on the area they cover.

- A local Area Network (LAN) is a network in an office, building or premises.

- Metropolitan Area Network (MAN) is a network within a city.

The following method is used to close the file of MS PowerPoint 2010.

- Click on the File tab and then click on the Close option.

- You can click on the close button appearing on the top right side of the window.

- The keyboard shortcut Ctrl + W can be used.

1. The full form of URL is Uniform Resource Locator. A uniform resource locator, colloquially called a web address.

2. In normal text ads, you define the display URL yourself: If your website address begins with a subdomain (for example, "support" in "support.google.com"), your display URL May include that subdomain.

3. In expanded text ads, your display URL is a combination of your website's domain (and, where applicable, subdomains) and the text in your “Path” field.

1. The memory which is used by RAM to store frequently used information is called cache memory.

2. Cache memory is much smaller than RAM, but it is much faster than RAM.

3. Recently used information is often stored in cache memory.

All are matched-

(a) Ctrl + Shift + C    (vi) For pasting

(b) Ctrl + Z                 (iv) Undo

(c) Ctrl + L                 (ii) The alignment of the text

(d) Ctrl + H                (i) To replace