A more thorough explanation:

Definition: Enrollment is the act of recording or registering something. This can include registering for a class or program, or recording information about a vessel used for coastal or inland navigation.

Example: When you enroll in college, you are registering for classes and officially becoming a student at that institution.

Example: In maritime law, enrollment refers to the recording and certification of vessels used for coastal or inland navigation. This is different from the registration of vessels used for foreign commerce. Enrollment shows the national character of a vessel used for coasting trade or home traffic, while registry is used to declare the nationality of a vessel used for foreign trade.

These examples illustrate how enrollment can refer to the act of registering for something, as well as the recording and certification of vessels used for specific types of navigation.