Are all shut off water valves the same?

I want to change two shut off valves and the house was built on the seventies and that is the reason of my question?

I will be looking forward to hearing from you soon.

Similar, but not the same. Most shutoff valves these days are of the ball design. The ball design can be a full flow or restricted valve.

Fixture valves are all over the map. Some look pretty and some do not.

1/2" copper tubing (5/8 OD) and 3/4 copper tubing (7/8" OD) may have been common in that era.