Question
You want to know what the differences are between built-ins, utilities, system calls and non-system calls. What are some examples of these?
Answer
You can break down the answer into four categories of Linux commands. You have commands that are either built-ins or utilities. You have commands that are either system calls or they are not. Here is a diagram for four types of commands and their examples:
| Builtins | Utilities | |
| System Calls | chown, kill, umask | mkdir, stat |
| Non-system Calls | echo | nmap |