This presentation discusses system calls and provides an overview of their key aspects: System calls provide an interface between processes and the operating system. They allow programs to request services from the OS like reading/writing files. There are different methods of passing parameters to the OS, such as via registers, parameter blocks, or pushing to the stack. System calls fall into categories including process control, file management, device management, information maintenance, and communication. An example is given of how system calls would be used in a program to copy data between two files.