"A talk" is an event where an author, a researcher, an expert, or some other person speaks to a large audience.
It's similar to a "speech", but a speech is more associated with politics, debating issues, or formal ceremonies. A "talk" is for explaining interesting ideas to people.
You "see" a talk or other performance. Some other things that you can "see" include:
- see a dance performance
- see a play
- see a concert
On the other hand, for TV and movies it's more common to say that you "watch a movie" or "watch TV".