11.6.2.1 describe the role of the uniform resource locator (URL)

URL - Uniform Resource Locator

URL is a web address that specifies the location of a resource, such as a webpage, image, video, or file, on the internet.

URLs play a crucial role in enabling users to access and navigate web content.

The primary role of a URL is to provide a unique identifier for a resource on the web. When a user types a URL into a web browser or clicks on a hyperlink, the browser uses the URL to request the corresponding resource from the web server that hosts it. The server responds to the request by sending the requested resource back to the user's browser, which then displays it on the user's device.

A URL typically consists of several parts, including

• the protocol (e.g., HTTP, HTTPS, FTP),
• the domain name or IP address of the web server, and
• the path to the specific resource on the server.

For example, the URL "https://www.example.com/index.html" specifies that the user wants to access the "index.html" file on the "www.example.com" web server using the HTTPS protocol.

There are two types of top-level domains (TLDs):

Generic Top-Level Domains (gTLDs): These are TLDs that are not associated with any specific country or geographic location. They are typically used for specific types of organizations or activities, such as ".com" for commercial entities, ".org" for non-profit organizations, ".edu" for educational institutions, ".net" for network infrastructure, and ".gov" for governmental entities.

All Generic Top-Level Domains (ccTLDs).

Country Code Top-Level Domains (ccTLDs): These are TLDs that are associated with specific countries or geographic locations. They are typically two-letter codes that represent the country, such as ".kz" for Kazakhstan, ".ru" for Russia, ".uk" for the United Kingdom, and so on. ccTLDs are managed by the respective countries or delegated authorities, and they may have specific registration requirements or restrictions. 

All CountryCode Top-Level Domains (ccTLDs).

Example URL

The URL "http://www.kst.nis.edu.kz" is a web address that specifies the location of a resource on the internet.

Here's a breakdown of each part of the URL:

• "http://" - This is the protocol used to transfer data from the web server to the web browser. In this case, it is the standard HTTP (Hypertext Transfer Protocol), which is commonly used for web browsing.
• "www" - This is a subdomain of the domain name, which stands for "World Wide Web". The "www" subdomain is commonly used to identify web servers that host public websites.
• "kst" - This is the fourth-level domain name, which identifies the organization that owns the website. In this case, it is "kst", which may be an abbreviation for the name of the organization or a keyword related to its activities.
• "nis" - This is the third-level domain name, which is a subdomain of the second-level domain name. It may further identify a specific department or location within the organization.
• "edu" - This is the second-level domain name, which identifies the type of organization. In this case, it is "edu", which is reserved for educational institutions.
• "kz" - This is the country code top-level domain (ccTLD), which identifies the country of origin for the website. In this case, it is "kz", which stands for Kazakhstan.

Overall, the URL "http://www.kst.nis.edu.kz" specifies the web address of a resource hosted on a web server belonging to an educational organization called "kst" located in Kazakhstan.

In addition to specifying the location of a resource, URLs can also contain query parameters that provide additional information about the resource or how it should be displayed. For example, a URL might include a parameter that specifies the language in which the resource should be displayed or a parameter that filters search results based on certain criteria.

Overall, URLs are an essential component of the web, allowing users to access and share web content quickly and easily. They provide a standardized way of identifying and accessing resources on the internet, making it possible for users to navigate the vast amount of content available online.

Questions:

1. What does URL stand for?
2. Explain the purpose of the URL.
3. Describe the difference between gTLDs and ccTLDs.

Exercises:

Exam questions: