Difference between Static and Shared libraries

In programming, a library is a collection of pre-compiled code that can be reused by programs for specific functionality. Based on how the library code is linked and loaded, libraries are classified into two types − static libraries and shared (dynamic) libraries.

Static Library

A static library is a library whose code is copied directly into the target executable at compile time by the linker. The resulting executable is self-contained and does not depend on external library files at runtime. Static libraries use the extensions .a (Linux) or .lib (Windows).

Shared Library

A shared library (also called a dynamic library) is loaded into memory at runtime by the operating system. Only the address of the library is stored in the executable, and the actual library code resides in a shared memory location accessible by all programs. Shared libraries use the extensions .so (Linux) or .dll (Windows).

Key Differences

Conclusion

Static libraries produce self-contained executables with no runtime dependencies but result in larger file sizes. Shared libraries reduce executable size and allow updates without recompilation, but the program depends on the library being available on the system at runtime.