strace is a tool that traces all system calls and signals.6 This refers to all data flow (inputs and outputs) across the user/kernel boundary. If this sounds like Greek to you, think of
strace as a spy that tells you everything your process asks your operating system to do and what the operating system triggers in your process. As soon as you start playing with
strace, you realize that your process is interacting with the OS much more than you think.