Front-end refers to the part with which the user directly interacts. Elements such as buttons, menus, login forms, and content that you see when you visit a web page or application belong to the front-end.

Front-end developers create the user experience using technologies such as HTML, CSS and JavaScript. Interactions such as actions, page transitions or animations that occur when the user clicks a button are carried out on the front-end side.

Back-end refers to the part that runs behind the web application or site with which the user does not directly interact. This part usually occurs on the server side and includes tasks such as database operations, user authentication, business logic operations. Back-end developers perform these operations using server-side programming languages (such as Python, Java, Ruby, C#) and database systems (such as MySQL, PostgreSQL, MongoDB). Back-end developers receive the requests sent by the front-end, process them and send the results to the front-end. Front-end and back-end work together to ensure the full functionality of a web application or site. While users interact through the front-end, the back-end performs operations and transfers the results to the front-end. This way, the user's demands are met and the application or site works correctly.