Hi Trey!
I have a whole bunch of articles on bundles & collaborations but to "summarize" everything:
Think of a bundle as a really great deal to get multiple products for one set price (or sometimes it can be free).
The bundle host, looks for "contributors" to join the bundle and submit a "paid product" for free into the bundle.
The benefit for the contributors is that they have an opportunity to grow their email list in exchange for giving away the paid product.
The benefit for the host is that all contributors are usually required to promote the bundle so every contributor gets access to another persons audience.
The people who grab the bundle get a ton of value from one product.
Did that make sense?