Какое из этих описаний относится к времени Present Perfect?(их может быть несколько )

1.the tense should be used to describe thoughts and states, with focus on them and not on the activities
2.The tense is used in order to describe something that is generally true
3.The tense is usually used when they describe an activity which is in progress at the present moment
4 person experience / changes which have already happened