Nether portals!

If I put out a nether portal, and then fire it up again, will it lead to the same place?

Anyway, I was thinking about doing a Nether Portal that I could “turn off” by pushing out one obsidian block with a sticky piston, but then I realized that the game might count it as a creation of a new portal once I turn it on again, and therefore it’ll lead to a different place in Nether. Can someone let me know how it works? Or are there better ways of creating a toggleable portal?

Yes, that’s also why you can make a easy travel because in the nether X blocks walking are less blocks in the overworld. It Will always Stay at the same place