group b strep...

So I had that test done and I'm group b strep. My doctor told me that there's a bacteria in me and I have to take antibiotics when I'm giving birth because it could affect my baby. Just curious how many other ladies are group b strep? And more info about what it actually is? My doctor said its nothing to worry about that a lot of women have it, & it's not an std or anything. But I'm just curious like what is it, and I get UTI's very often could that be the reason as to why I'm getting the UTI's?