Some colleges allow for both “informal” and “formal” processes. A formal process is the default presumption, and the informal route usually requires the consent of all parties involved including you, the complainant, and the college.
Informal processes are usually less rigid, provide you with less protections, but also have less serious penalties. In the event an informal process is agreed upon by all parties, it usually involves some sort of admission to the allegations, as usually there are no formal investigations or hearings, and then there is a negotiation as to appropriate punishment or resolution.
Formal processes proceed along more official lines as detailed below.