On a very high level, Prolog only has a single data type, called term. In Prolog, all data is represented by Prolog terms. Terms are defined inductively:
x
, test
and 'quotes and space'
._
.42
and 42.42
.T1
, T2
, ..., T_n
are terms, then F(T1
,T2
,...,T_n
) is also a term, where F is called the functor of the compound term.