The Internet is a global network of interconnected computers that communicates via TCP/IP.

The Web (World Wide Web) is an information system where documents and other resources are available over the Internet. Documents are transferred via HTTP.

HTTP Requests (How it works example...)

-Request: I would like some information about cars, please!

-Response: Ok, here you go!

Some Definitions

Web Server- A system that can satisfy requests on the Web.

Client- The sub-system that accesses a server.

Browser- The translation of the server's information to a visual and practical interface for the user. It may use languages such as HTML, JavaScript and CSS.

Front-End and Back-End Process

The Front-End is where the end-user interacts with an interface to make requests, it is visually appealing, understandable and intuitive for the customer experience and interactivity.

The Back-End receives the Front-End's request and starts to process it in its data and information servers storage, to get an approximation of the user's request.

Finally, the request is presented to the user in the Front-End with the help of programming languages like HTML, Javascript and CSS.

Let's say in summary that the Front-End is what initially the user interacts with and the Back-End is where all the internal processes take place that don't require the user to be manipulating them, but take place as pre-conditional and automatic processes that happen "behind the curtains" to calculate, manipulate and transform requests into responses as output.