Difference between .classpath and MANIFEST.MF

What is the difference between adding a dependency jar to the .classpath file in a RAD project and adding the dependency to the MANIFEST.MF file?

• .classpath file is specific to IDE (RAD, and also Eclipse in general). It is for setting classpath entry for compile and execute your project in your IDE.
  MANIFEST.MF is standard (independent from IDE you used during development) way to set path to libraries your jar needs runtime.

• So MANIFEST.mf will not be used for compile time? Only for runtime?
  Exactly, it is for runtime, not for compiling. Though some IDEs can have functionality where adding some dependency to the MANIFEST.MF causes dependency to be added to the IDE's project configuration files as well.