What happens inside a computer?

A computer stores 0s and 1s, runs a processor that follows instructions, and uses memory for what it is doing right now. Storage (SSD/HDD) is for files that stay after you shut down.

The operating system (like Windows) is the manager: files, windows, internet, apps. Office tools sit on top of that.

If this is new, start with Computer Foundation. You do not jump to coding first.