code-server - development tool, lemp - server application, are different software used for web development
lemp is the server setup where your application actually runs and is accessed by the public internet. code-server is the editor you use to write the code for that application, accessed privately by the developer through a browser

tool to run visual studio code in a browser on a remote server, providing a consistent, web-based integrated development environment
single application that provides a browser-based code editor experience
to provide a flexible and convenient way for developers to write, edit, and manage code from any device with a web browser, centralizing the development environment