How is the perfect tense formed?

The perfect tense is formed from : 
The auxiliary verb haber + the past participle of the verb , either ending in -ADO(-ar verbs) or -IDO(-er and -ir verbs) 
He hablado, He comido, He vivido. 
 
Example : COMER 
He comido 
Has comido 
Ha comido 
Hemos comido
Habéis comido 
Han comido