Refers to a group of people sent on an official mission, typically diplomatic, governmental, or organizational.
The Japanese delegation attended the UN General Assembly.
An economic mission is scheduled to visit Southeast Asia next week.
使節 refers to an individual envoy or delegate, whereas 使節団 is the group or delegation as a whole.
diplomatic mission
Compound of 使節 (envoy, delegate) and 団 (group, body). The word 使節 itself is composed of 使 (use, send on a mission) and 節 (node, section, here implying a person of standing).