Socket programming in course "Penetration Testing: Preliminary Skills & Programming"

Hello All,
I am currently preparing for eJPT and going through course " Penetration Testing: Preliminary Skills & Programming". I was enjoying the module “C++” pretty much but got a bit disappointed when I saw the lab exercise at the end of the course. The lab is good and program created is also very good but the problem is I am not able to understand the program and most the elements used in the program is not covered under the module or any other previous course. The module introduce basic concepts of C++ but program starts with structure and socket programming which is advanced level topic and should be covered in great depth before directly using in the lab.

I do agree that references are provided but I am expecting to cover all the required information in the course itself. Kindly help me in making the concepts of socket programming clear.