A relocatable file holds code and data suitable for linking with other object files to create an executable or a shared object file.
Executable File=可执行文件
An executable file holds a program suitable for execution
Shared Object File=共享对象文件
A shared object file holds code and data suitable for linking in two contexts. First, the link editor may process it with other relocatable and shared object files to create another object file.
Second, the dynamic linker combines it with an executable file and other shared objects to create a process image
