What happens after you type a URL?
A classic question. I wanted to trace it honestly, from keypress to the machine deciding what to do.
What I thought
The computer “just knows” what to do when I press a key. It felt like magic that I never questioned.
What actually happens
A keypress is an electrical signal that becomes a number. Software layers turn that number into a character, the character into text, and the text into an instruction something can act on.
Underneath, the processor is only ever doing very small, very fast, very literal steps — fetch an instruction, do it, repeat.
What confused me
Where the “understanding” happens. The answer is that it doesn’t, really — meaning is built up in layers, and each layer only does something simple.
What finally made sense
A computer doesn’t know what to do. It follows instructions that people arranged so carefully that the result looks like knowing.
What I’m looking at next
How an operating system decides which program runs at any given moment.
Written while figuring it out. Possibly wrong in places — that’s part of learning.
What actually happens when a browser loads a page?