The difference between a syscall and a library function call is that a syscall crosses protection boundaries. Implementations differ, but where a library (even

The difference between a syscall and a library function call is that a syscall crosses protection boundaries. Implementations differ, but where a library (even the lowest-level OS library like libc) runs in the context of the application and can be invoked with a regular "store pointer and jump" method call, a syscall usually involves transfering control to the kernel through a software interrupt.