Instead of accessing a resource in the internet by using IP addresses, URL (Uniform Resource Locator) is a better way to remember and access a particular resource. There are 4 sections in a typical URL:
1) Protocol: A protocol could be http, file, ftp, and gopher. This is the way by which a resource will be accessed.
2) Host Name: This is the name of the resource. You can also use IP address in here.
3) Port Number: It is used to identify a port. For Example: 80 for HTTP (Hypertext Transfer Protocol), 20 and 21 for FTP (File Transfer Protocol).
4) Path of file: It is used to access a particular file.