Front-end
The front-end of a website is the part a user sees and directly interacts with. A front-end developer builds the front-end based on the design by the designer. The front-end developer uses HTML, CSS, and JavaScript to build the front-end, which the browser renders to present it to the user.
The front-end works together with the back-end to make using a website possible. The front-end can receive input from the user, for example an order in a webshop or an e-mail to send in an e-mail application. The back-end then receives this information in order to process it further. After this information is processed, the response from the back-end can then be rendered in the front-end.