Static library vs dynamic library

Dynamic library – a unit of code and/or assets linked at runtime that may change . However, only Apple is allowed to create dynamic libraries for iOS . You’re not allowed to create these, as this will get your app rejected. (See this other SO post for confirmation and reasoning on such).

Dynamic linking has the following advantages over static linking: Multiple processes that load the same DLL at the same base address share a single copy of the DLL in physical memory . Doing this saves system memory and reduces swapping.

Dynamic or shared libraries occur as separate files outside of the executable files . Thus, it only needs one copy of the library’s files at runtime. At compile time, static libraries stay locked into a program. It contains the file’s programs holding a copy of the library’s files at compile time.

Static libraries, while reusable in multiple programs, are locked into a program at compile time. Dynamic, or shared libraries on the other hand, exist as separate files outside of the executable file . … In contrast, a dynamic library can be modified without a need to re-compile.14 May 2017

A static library must be linked into the final executable; it becomes part of the executable and follows it wherever it goes. A dynamic library is loaded every time the executable is executed and remains separate from the executable as a DLL file.

Dynamic libraries are a collection of object files which are referenced at build time to give the executable information how they will eventually be used, but they aren’t used until run time . In other words, these objects are dynamically linked into executables that use them.

When a file is compiled with a dynamic library, instead of copying the actual object code contained in the library, the linker simply scans the code contained and checks for missing symbols .