To correct a bit what Joey said, a Record is a specific data structure that can hold any number of Structures, Entity Records (which aren't really records, but more like simple Structures) and Simple Types (like Integer and Text). It is like a makeshift Structure which is created on the fly by an Aggregate, but something you can also create manually (though that's a bit cumbersome).
Lists may contain Records, but also Structures, Entity Records and Simple Types. However, a List can contain only a single type of Record/Structure/etc., so each element in a List has the same type.
I am wondering how you came to your question though, and why it was difficult for you to find the answer in the documentation?