strings and atoms with JPL

Hello,

I am wondering how can strings be used with JPL, and more
generally, what is the link between atoms and strings.

What I think is :
strings are atoms with " ' " before and after.

In JPL, there seems to be no distinction between a
string and a "classical" atom.

Are things like that ? Am I missing something ?

I am asking this because I am wondering if strings in JPL should
be treated differently than atoms or not, more specifically,
should I think that any string (used in the context of JPl of
course, in a term for example) *is* an atom ? Or is there a
difference that make strings to be treated differently than atoms ?

Thanks you for your help :)

Victor