Answer 1

Header Files are files containing function definitions and other data to use in accordance with your program. These can be libraries such as cURL, libssh, winsock, etc.

Library files are files that contain the data and function symbol definitions for using these header files. These can either be dynamic or static libraries.

Static libraries link all symbols to your program as a whole, while dynamic libraries load them into memory when they are called. This can hurt the program when it comes to obfuscation, but it is much less resource consuming.