What is RVA and VA?

Please explain what RVA and VA means

From stackoverflow Lee Jae Beom

• See the wikipedia article on COFF (Common Object File Format):

  Relative Virtual Addresses (RVAs) are not to be confused with standard virtual addresses. A relative virtual address is the virtual address of an object from the file once it is loaded into memory, minus the base address of the file image. If the file were to be mapped literally from disk to memory, the RVA would be the same as that of the offset into the file, but this is actually quite unusual.

  Lee Jae Beom : Why people created concept of RVA? for what?

  Stephen Kellett : It is used for quickly identifying the location inside a DLL at which data resides when you have no idea at the time of writing the code at what address the DLL will be loaded.
  From tvanfosson