Eclipse: Difference between clean, build and publish

Question

I am using eclipse with tomcat. On the server (right-click)tab you have the options: Clean, Publish and Clean Tomcat Work directory, What do these options really do a

Answer 1

Build: compile changed source files on the build path in the project
Clean: compile all source files on the build path in the project
Publish: Deploying the updated project in the web server instance