In spoken English the words is and has are sometimes contracted to 's.
Have a look at the following examples:
1) He's listening to music. -> He is listening to music.
2) He's listened to music. -> He has listened to music.
In sentence 1) the 's is followed by listening. This verb has the ending -ing. It is Present Progressive (is + infinitive + -ing).
In sentence 2) the 's is followed by listened. This verb has the ending -ed. It is Present Perfect (regular: has + infinitive + -ed or
irregular: has + 3rd column of the irregular verbs).
The verb following the 's tells you whether it's is or has.