> Frame
> comment

The BALL source the term only in it's most basic meaning: as a collection of attributes (slots) having values (a.k.a. key-value-pairs) plus updates controlled by other properties of the same frame.

In a way one can say: it's used to avoid the rather similar term object to steer clear of name conflicts in various possible implementation languages.

Recently the type :message: has been used as synonym. (Though it's not clear that we want this to stay.)