What is the difference between the perfect and the imperfect tense?

1.The perfect tense is used to describe completed actions, in other words, those that have a clear beginning and end point. It can also be used to talk about an event, or a chain of events, that only happened once. For example:Hier j'ai joué au foot de 14h à 15h. Yesterday I played football from 2pm to 3pm.
2.On the other hand, the imperfect tense is used to describe incomplete actions, or, those which don't have a clear beginning or end point. It is also commonly used to talk about events that happened on a regular basis in the past. For example: Quand j'etais petit, je jouais au foot toutes les semaines. When I was younger, I played football every week. 3. When used together in a sentence, the imperfect is used to describe an action happening in the background that was then interrupted by an another action described using the perfect tense. For example: Je regardais la télé quand la téléphone a sonné.I was watching television when the phone rang.