When you "put something together", it means that you make something by collecting materials or information from different places. In the example above, you can imagine that the presentation is created using information, notes, photos, and graphics from different sources.
Some other things that people sometimes "put together" include:
- put together an event
- put together a portfolio
- put together a business plan
When you use a short pronoun like "it", "they", "something", etc. it goes between "put" and "together":
We put it together quickly.
We can put something together later this week.
When you use a noun or noun phrase, it goes after "put together".