What is Internet?
The internet is a massive network of networks, a networking infrastructure. It connects millions of computers together globally, forming a network in which any computer can communicate with any other computer as long as they are both connected to the internet. Information that travels over the internet does so via a variety of languages known as protocols.
What is Web?
The World Wide Web, or simply web, is a way of accessing information over the medium of the internet. It is an information-sharing model that is built on top of the internet. The web uses the HTTP protocol, only one of the languages spoken over the internet, to transmit data. Web services, which use HTTP to allow applications to communicate in order to exchange business logic, use the the web to share information. The web also utilizes browsers, such as Internet Explorer or Firefox, to access Web documents called webpages that are linked to each other via hyperlinks. Web documents also contain graphics, sounds, text and video.
The Internet is a global network of networks while the Web, is collection of information which is accessed via the Internet. Another way to look at this difference is; the Internet is infrastructure while the Web is service on top of that infrastructure.
What is e-mail?
Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email operates across computer networks, which is primarily the Internet.
Originally an ASCII text-only communications medium, Internet email was extended by Multipurpose Internet Mail Extensions (MIME) to carry text in other character sets and multimedia content attachments. International email, with internationalized email addresses using UTF-8, has been standardized, but as of 2017 it has not been widely adopted.