Part 102 is a CAA rule which set out the requirements which must be adhered to be issued a Part 102 operating certificate. Furthermore, it sets out the ongoing obligations to ensure the operator remains compliant with the rule to provide a safe operating environment for the public and other aircraft. These are incorporated into an exposition (which a fancy way of say a series of manuals) It is a live document and therefore should not be viewed as a document which can be ignored once certification is issued.
Examples of what can be included in the exposition are: training for pilots, competency checks, standard operating procedures, specific operating procedures for non 101 operations, reporting and maintenance.