
Certified GKH Gardening Expert
If you live in an area that freezes in the winter, and I see you do (zone 5b), begonias will need to be overwintered. I believe yours is a tuberous begonia. Here is how to overwinter them:

Certified GKH Gardening Expert
This is Begonia grandis subsp. grandis in double flower arrangement.
Technically, it is hardy in your area, but only barely. In order to ensure that it comes back, you will want to mulch, heavily.
This colletion of articles will give you information about many types of begonias: