Tense is a form a verb takes to show the time it happened.
It actually describes when any action happened with respect to time.
Tenses are divided mainly into 3 types Past Tense,Present Tense,Future Tense
Now, each of these 3 types have 4 sub-types. : Simple, Continuous, Perfect and Perfect Continuous.
You can consider it as a Family tree where, Grand Father, Tense is having 3 children(Past, Present and Future)
each Parent is having four sons with same names : Simple, Continuous, Perfect and Perfect Continuous.
combining them all becomes 12 siblings.
Verbs are mainly divided into 5 main forms which are
Base form, we will denote it as V1
Past Form, we will denote it as V2
Past participle we will denote it as V3,
'S/Es form', we will denote it as Vs/es, and
'Ing form' which we will denote as Ving.
Now, lets look into an example of verb, play.
the base form of play is Play, in past form
it is played, in past participle form it is played,
in s/es form, it is plays,
and in Ing form it is playing