Ovulation Test Newbie

Selena
Hi, I've never used ovulation tests before and was wondering if anyone could tell me how exactly they work? Do you get two lines when ovulatating? How many days do you test for? Eg. If I test on Monday and I am ovulating, do I test Tuesday and Wednesday too?
Sorry if this is like blatantly obvious I just don't know much about this kind of thing despite having a two year old daughter! Thanks