We all use URLs to visit webpages and other resources on the web. The URL is an address that sends users to a specific resource online, such as a webpage, video or other document or resource. When you search Google, for example, the search results will display the URL of the resources that match your search query. The title in search results is simply a hyperlink to the URL of the resource.
The first part of the URL is called a protocol identifier and it indicates what protocol to use, and the second part is called a resource name and it specifies the IP address or the domain name where the resource is located. The protocol identifier and the resource name are separated by a colon and two forward slashes.
For example, the two URLs below point to two different files at the domain webopedia.com. The first specifies an executable file that should be fetched using the FTP protocol; the second specifies a webpage that should be fetched using the HTTP protocol:
Accessing a URL that ends in .com, .html, or .htm will display a webpage located at that address. If, for example, you visit a URL that ends in .jpg or .png you can expect to view an image file.
The term "web address" is a synonym for a URL that uses the HTTP or HTTPS protocol. The Uniform Resource Locator (URL) was developed by Tim Berners-Lee in 1994 and the Internet Engineering Task Force (IETF) URI working group. Today, the format of the URL has not changed. The URL format is specified in RFC 1738 Uniform Resource Locators (URL).
Note that in object-oriented programming, such as Java, programs can use a class (a category of objects) called URL. You can create a URL object to represent the URL address.
Source : https://www.webopedia.com