Question

what do you mean by tense ?

Answer 1

Tense is a verb used to indicate the time

Answer 2

Tense (noun): a verb-based method used to indicate the time, and sometimes the continuation or completeness, of an action or state in relation to the time of speaking. ORIGIN Latin tempus "time"

We cannot talk of tenses without considering two components of many English tenses: time and aspect. In simple terms...

Time expresses:

past - before now
present - now, or any time that includes now
future - after now

Aspect can be:

progressive - uncompleted action
perfective - completed action or state