It is both. It means the end, but it adds the idea that the way it ended was appropriate for the circumstances.
Student or Learner
It was a fitting conclusion to the memorable occasion.
Does the word conclusion in the above sentence mean 'end' or something we decide after thinking about all the information connected with the situation?
I can't find a meaning of 'decision' in that sentence. "The fireworks were a fitting conclusion to the memorable occasion."
In any case, 'conclusion' can mean either 'end' or 'decision' - rarely both. My conclusion (decision) about an issue might signal the end of my thinking about it, but not necessarily, and that's not the meaning."
It was a fitting conclusion (ending) to the memorable occasion.
The "ending" of the occasion was memorable. Perhaps it was an inspirational speech or something grand, like in the Olympics.