Loader
In plain terms
The OS component that loads a program into memory to run.
Going deeper
A loader places an executable's code and data into memory, sets up the runtime, and starts execution. It readies a program to run.
Under the hood
Handles relocation and dynamic library loading; the bridge from on-disk binary to running process.
Examples
Program startup, dynamic linking, memory loading, OS execution, ELF.
Think of it like...
Like a stagehand setting up the props and actors before the show begins.