A shared object or shared library is a computer file that contains executable code that is designed to be used by multiple programs or libraries at runtime.
On Windows systems, these are commonly known as Dynamic Link Libraries (DLLs)
Shared objects provide the advantage of saving disk space. Every program using a library doesn’t have to include it in its final executable file; only one copy needs to be maintained on disk.
This also provides an advantage with system maintenance. If a bug is discovered in a library, only one copy of the library needs to be updated on disk. Conversely, if all binaries were static-linked, every program utilizing the affected library would need to be recompiled.