Verb conjugation refers to how a verb changes to show a different person, tense, number or mood.
Person:
In English, we have six different persons: first person singular (I), second person singular (you), third person singular (he/she/it/one), first person plural (we), second person plural (you), and third person plural (they). We must conjugate a verb for each person. The verb to be is a particularly notable verb for conjugation because it’s irregular.