In MS Windows PE file terms, the .reloc section holds a table of base relocations - a list of places in the image where the difference between the linker-assumed load address and the actual load address needs to be taken into account.
A base relocation is an adjustment to an instruction or initialized variable value (locations of static variables, string literals and so on).
The relocation directory is a sequence of chunks where each chunk contains the relocation information for 4 KB of the image.
If the loader can load the image at the linker's preferred base address, the loader ignores the relocation information in this section.