Is there a general word for the "subevents" at an event of some sort? For instance, at a conference, I guess I could probably use "talk" or "presentation"; at a fair I could perhaps use "presentation" or "demonstration", and so on – but is there a common word that I could use for any "subevent" at any kind of event? I've thought about "feature, "item" and "slot", but when I look up these words in dictionaries, I don't find unequivocal support for either of them in this context.
The first [REQUESTED WORD] starts at 9.
There are many interesting [REQUESTED WORD] on today's programme.