An affix is something in linguistics which attaches to the word it modifies. For example, the English plural suffix 's'/'es' is an affix, as shown in "books on the shelf". The suffix attaches to the word made plural - 'book'.
A clitic is something that attaches to something other than the word it modifies. An example of this in English is the possessive 's. Adding that to the previous example gives "books on the shelf's". Here, the possessive clitic is attached to 'shelf', even though the word it's actually modifying (the possessor) is 'books'.
This is the technical term for what Trique uses frequently (and I didn't know the name of until now). In Trique, personal and possessive pronouns often become clitics when following certain other types of words. Trique also uses clitic doubling, in some cases.