Every beginner’s guide to photography starts with the rule of thirds. Divide the frame into a three by three grid, put your subject on a line or an intersection, done. It works, which is why it survives.
It’s also older than photography. An English engraver named John Thomas Smith gave it a name in the 1790s, writing about landscape painting. He noticed that scenes looked better when the main elements didn’t sit in the middle.
Where it fails
Put a subject dead center and you get calm, formality, confrontation. Portraits in old passport style do this. So do a lot of great architectural shots, where symmetry is the whole point. A grid can’t tell you that.
The rule also breaks down with movement. A runner needs space in front of them to run into. A person looking out of frame needs room to look. Those decisions come from the subject, not the grid.
Use it as a starting point
Turn on the grid overlay on your camera and see what it does to your habits. Then turn it off for a week. You’ll notice which shots you’d have framed differently, and that’s the useful part.
Rules are for people learning. After that you just look.