Operating System Full Course.L-2.1: Process Synchronization | Race Condition | Cooperative Indepe... . In this playlist first we'll see introduction to operating system and then we'll discuss what are the functionalities of operating system .So what operating system basically is? Operating system is a system software. Means it's a software ,which is in your system. And its basic functionality or definition is.... It works as a interface between user and hardware. It's in very simple language that operating system is providing interaction between user and hardware.