What is the difference between using MFC in a Static Library and the use of MFC in a Shared DLL?

If you choose to use the MFC in a Shared DLL, your compiled program does not contain the MFC libraries, so the files will be small, but if your program moves directly to a machine that does not have MFC installed, it may cause MFC DLLs to be found.

If you choose to use the MFC in a Static library, then your compiled program directly contains the library that calls the parts of MFC, the file may be larger, but can be moved directly to other machines to run.

The former is a dynamic connection, releasing the DLL file to take with MFC.

The latter is a static link that publishes DLL files without MFC.

If the executable file has only one, using the former, the execution speed is fast, but the file is larger.
If the executable file is multiple, use the latter because the DLL file is shared, so the total file volume is reduced.
A single file is also small. Load the execution block, but run slower than the former.

Used in a static library:
Use Lib files. Lib is a compiled binary file that can be statically linked with your project to become an EXE.
Used in a shared DLL:
Using a DLL file, the function implementation is hidden inside the DLL file, and your project is compiled into an EXE file, and the DLL is called by the runtime.