Extension service and Educational activity

Extension service noun - An educational opportunity provided by colleges and universities to people who are not enrolled as regular students.

Educational activity and extension service are semantically related. In some cases you can use "Educational activity" instead a noun phrase "Extension service".

Educational activity noun - The activities of educating or instructing; activities that impart knowledge or skill.

Extension service and educational activity are semantically related. Sometimes you can replace phrase "Extension service" with "Educational activity", this phrases are similar.