in realtà farebbe meglio a non usarla e in generale ad evitare per quanto possibile le System
a livello di operazioni sono parecchio onerose e in più non è portabile in tutti i sistemi

un esempio di ciò che fa la chiamata system()
t's a very expensive and resource heavy function call. It's like using a bulldozer to open your front door. It works, but the key is cleaner, easier, cheaper. What system() does is:

suspend your program

call the operating system

open an operating system shell (relaunches the O/S in a sub-process)

the O/S must now find the PAUSE command

allocate the memory to execute the command

execute the command and wait for a keystroke

deallocate the memory

exit the OS

resume your program

There are much cleaner ways included in the language itself that make all this unnessesary.