As a general rule, the majority of committees have at least one subcommittee, which can have different names, but only one official name—the Subcommittee on Agenda and Procedure—often referred to as the steering committee. It has a limited number of members. Usually, it's made up of the chair and a member from each party, depending on party representation in the House.
Not all committees have a working subcommittee, but many do to help them plan future business. Subcommittees can propose topics for study, for example. The subcommittee has discussions and, then, reports to the committee, which considers the subcommittee's recommendations and makes any necessary changes. Once the committee adopts the recommendation, it becomes the decision of the committee. A lot of the groundwork is done by the subcommittee.