www stands for - World Wide Web is called because there are sites all over the world that are connected by links between them (hyperlinks) forming a web.
Hypertext Transfer Protocol (often abbreviated to HTTP) is a communications protocol. It is used to send and receive webpages and files on the internet. It was developed by Tim Berners-Lee and is now coordinated by the W3C.
A more secure version of HTTP is called HTTPS (Hypertext Transfer Protocol Secure). This contains https:// at the beginning of the URL. It encrypts all the information that is sent and received. This can stop malicious users such as hackers from stealing the information and is often used on payment websites.
The Domain Name System (DNS) is a system used to convert a computer's host name into an IP address on the Internet. For example, if a computer needs to communicate with the web server example.net, your computer needs the IP address of the web server example.net. It is the job of the DNS to convert the host name to the IP address of the web server. It is sometimes called the Internet's telephone book because it converts a Website's name that people know, to a number that the Internet actually uses.
