Fullstack development refers to the development of both the frontend and backend components of a web application. The frontend component typically consists of the user interface that users interact with, such as HTML, CSS, and JavaScript, while the backend component consists of the server-side code that processes requests from the frontend and communicates with databases and other services.

A fullstack developer is responsible for developing and maintaining both the frontend and backend components of a web application. This includes designing and implementing user interfaces, developing server-side logic, writing API endpoints, and managing databases.