So, the percent isn't really enough to get answers; there's going to be a lot more information here.
But generally speaking, in American tech companies, the current norm is something like "a four year monthly vesting with a one year cliff."
If you have that, what that would mean was that you got no stock for your first year. If you got fired in month 11, you'd be out in the cold on equity completely. This is a safety measure for the company: you can't always be sure you're hiring the right person.
But if you get past the cliff, then you receive all the stock you would have gotten during that time.
A four year monthly vesting means that you break your stock up into 48 monthly groups, and receive it in those pieces one at a time. So, assuming the one year cliff, you'd get one quarter of your promise the day that cliff ticked over, then 1/48 of your promise every month thereafter until, after four years, it was fulfilled.
Meaning if you got a 1% offer (which is large,) and you got fired at exactly year 2 of a four year vesting, you would walk away with one half of one percent of the company.
There is a book that I read which I found very, very helpful in understanding the arcana. It's called "Venture Hacks," and despite that the title pretty obviously panders to software nerds, it is chock full of very valuable information, and is presented in a way that I found very, very readable.
It is quite uncommon for a company to give you a percentage up front. Hiring is difficult; sometimes a complete clown looks really sophisticated, and two months in, when you realize they basically just lied their way through the interview, you don't want to send them away owning a piece of your thing after having done nothing.
But, the amount of information you gave us is incomplete, so we cannot actually give you a solid answer.