What is a URL?

URL (Uniform Resource Locator), Uniform Resource Locator, used to locate resources on the Internet, commonly known as URL. The explanation of each part of
scheme://host.domain:port/path/filename
:
scheme: defines the type of Internet service. Common protocols are http, https, ftp, file, the common type is http, and https is the encrypted network transmission;
host: defines the domain host, the default host of http is www;
domain: defines the Internet domain name, such as w3school .com.cn;
port: defines the port number on the host, the default port number of http is 80;
path: defines the path of the file on the server, if not filled, it is the root directory of the website
filename: defines the document and resource first name