They allow one to keep in touch with people (7)

I believe the answer is:

letters

I'm a little stuck... Click here to teach me more about this clue!

But I can't explain it at all! Could you help me understand?

(Other definitions for letters that I've seen before include "Correspondence" , "They are bound to look after tenants" , "A, B, C, D etc" , "eg E G" , "Epistles" .)

Want a hint initially instead of a full solution? Install my app