High Quality Content by WIKIPEDIA articles! A baseball cap is a type of soft cap with a rounded stiff brim. The front of the cap typically contains designs or logos of sports teams (namely baseball teams), (or names of relevant companies, when used as a commercial marketing technique). The back of the cap may be "fitted" to the wearer`s head size or it may have a plastic, Velcro, or elastic adjuster so that it can be quickly adjusted to fit different wearers.