Coding is the process of writing instructions for a computer to execute. It involves writing code, which is a set of instructions in a programming language, such as HTML, CSS, JavaScript, Python, or Ruby. The code is written using a text editor and then compiled, or translated, into a language the computer can understand. Once compiled, the code can be tested and debugged to ensure it works properly. Finally, the code can be deployed to a server, where it can be accessed and used by others.