What do you call this behavior, and how do I stop it (Firefox)

Recently my settings all got trashed, and I’m trying to re-set them back to the way I want, but I don’t remember how to change some of them.

When I am filling in a field on a web page in Firefox, it will throw up a small box with things that I have previously typed in the same (or sometimes in a similar) box that match what I have typed so far. I don’t like this, it gets in the way sometimes.

So what do you call this behavior?

How do I stop it? I’ve looked in Options and I don’t see anything like that there.
Roddy

Tools -> Options -> Privacy

History

Firefox will: ‘Use Custom Settings for History’

uncheck ‘remember search and form history’

Autofill.