Forced would be against a person's will. Often girls growing up in immigrant families grow up with the idea that their families will choose a spouse for them, and it's something that's quite natural to them that they might not be opposed to. It depends. Usually a family does want the best for their daughter, so they would try to get someone who will take care of their daughter. But sometimes that's not the case, which is very disappointing, if a family finds someone who is not going to take care of their daughter. But usually families also try that.
Those are arranged marriages, where the family finds someone and the young people agree to get into such a marriage.
A forced marriage would be when they don't agree, or they have met the person or heard about the person and don't want to get into it.