petting vs caressing

petting and caressing both are nouns.

Word	Noun	Adjective	Verb	Adverb
petting	Yes	No	No	No
caressing	Yes	No	No	No

As nouns, petting and caressing are synonyms defined as:

petting and caressing: affectionate play (or foreplay without contact with the genital organs)

Other synonyms of petting include cuddling, fondling, hugging, kissing, necking, smooching, snuggling.

petting (noun)	caressing (noun)
affectionate play (or foreplay without contact with the genital organs)	affectionate play (or foreplay without contact with the genital organs)