What are tenses

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"

The concept of tense in English is a method that we use to refer to time - past, present and future. Many languages use tense to talk about time. Other languages have no concept of tense at all, but of course they can still talk about time, using different methods.