In the development process, only static libraries are used. According to the information on the Internet, the iOS system only supports static libraries, not dynamic libraries.

Generally speaking, the framework encapsulates the library, as well as the corresponding header files and referenced resource files (if any).

Static library

When linking, it is completely copied into the executable file. If it is used many times, there will be multiple redundant copies.

Dynamic warehouse

When linked, it will not be copied. When the program is running, it is dynamically loaded into memory by the system for the program to call. The system is only loaded once, and multiple programs are used to save memory.

To sum up, it is actually the difference between loading timing and loading times.