Q.Expand the following:

This is a plain theory question — you are asked to expand three standard acronyms from computer networking.

1. ARPANET — Advanced Research Projects Agency Network. It was the first operational packet-switching network and a direct predecessor of the modern Internet, developed by the U.S. Department of Defense.
2. ISP — Internet Service Provider. An organisation that provides individuals and companies access to the Internet, along with related services such as email, web hosting, and domain registration.
3. URL — Uniform Resource Locator. A reference or address used to access a resource on the Internet, specifying the protocol (e.g., http), domain name, and often a path to a specific file or page.
   ✓Final answer

   The expansions are: ARPANET — Advanced Research Projects Agency Network; ISP — Internet Service Provider; URL — Uniform Resource Locator.

This is a straightforward acronym-expansion question, common in Class 12 Informatics Practices and Computer Science exams. The examiner wants to test whether you know the full forms of these key terms, not just what they stand for but also a bit of context about each.

Let's take them one by one.

1. ARPANET ARPANET stands for Advanced Research Projects Agency Network. It was the pioneering wide-area packet-switching network developed by the US Department of Defense's Advanced Research Projects Agency (ARPA) in the late 1960s. ARPANET is widely considered the technical precursor to the modern Internet — it was the first network to implement the TCP/IP protocol suite, which is the foundation of today's Internet communication.
   Note

   Many students confuse ARPANET with the Internet itself. ARPANET was the prototype; the Internet as we know it emerged later when multiple networks (including ARPANET) were interconnected using TCP/IP.

2. ISP ISP stands for Internet Service Provider. An ISP is a company or organization that provides individuals and other organizations with access to the Internet. Examples include BSNL, Airtel, Jio, and ACT Fibernet in India. ISPs offer various connection technologies such as DSL, fiber optic, cable, satellite, and mobile data (4G/5G). They also typically provide related services like email accounts, web hosting, and domain registration.
   Tip

   In exam questions, remember that an ISP is the gateway between your home/office network and the global Internet. Without an ISP, you cannot connect to the Internet.

3. URL URL stands for Uniform Resource Locator. A URL is the address used to access a resource on the Internet — typically a web page, but it can also point to images, videos, files, or other resources. A URL has a standard structure: protocol://domain-name/path-to-resource. For example, in https://www.example.com/about, https is the protocol, www.example.com is the domain name, and /about is the path.
   Watch out

   A common mistake is to say URL stands for "Universal Resource Locator". The correct word is Uniform — this is a standardised term from the W3C and IETF specifications. Always write "Uniform Resource Locator" in your answer.

   ✓Final answer

   The expansions are: (a) ARPANET — Advanced Research Projects Agency Network; (b) ISP — Internet Service Provider; (c) URL — Uniform Resource Locator.