Time is a measurement between events or moments. It is a measurement of progress of existence and events from past to future through present.
Time is a fundamental part of the universe and it is a fundamental physical quantity. Time is referred to fourth dimension along 3 spatial dimension.
Okay now understand this with an example. Imagine that there is no any time. you don’t know that what is time means there is no any existence of time. Okay now imagine that there are two train, Train A and Train B. Both trains are boarding together but Train A reached first at station and Train B reached at station after train A. But you cannot give difference between both trains. If you don’t use Time then both trains are same. If we want to measure both train then we must need a measurement word for difference between both trains. We need to use a measurement for describe the event between both trains.
Okay now take an another example. Imagine that now you are reading my post and after reading my post you will take a little nap and after then you will read my post again. So if we do not consider time then there are first and the last thing (you are reading my post) are same but actually they are not same. So we need a term for measurement and describe the process and difference between events. If we do not use time then we cannot understand the things.
In another hand we use time for fourth dimension. Generally we use 4 dimension for describe the position of anything. We use x, y, z and t(time) for describe position of anything in space. Einstein use time as a fourth dimension in his The Theory of Special Relativity.
You can understand time in a different way. Time is helpful in describe the existence of anything. If you are living and breathing then time will help you for give your present existence. If anybody dead then also time will be able to give past existence for this dead man and if we will dead tomorrow then also time will be help to give our future existence. So time gives us a existence for our past, present and future. So time is a measurement between events from the past to the future through present.
In physics, time give a main role to describe motion and force.
There is a very interesting thing. We can measure the time but we cannot feel and experience the time.We can say that if entropy is increasing then time is increasing. Have you ever asked a question that why we born younger and grow older? Think……………………………………………………………………………………………………………
Because entropy increasing, so time increasing.
You can ask a question that if a stone fall at ground and there is nobody to heart it then it makes a sound? off course, yes. So if time flows without entropy and there is no one for experience it, then still it is a time? yes there is still it is a time.
So, we can measure time but we can not feel and experience it.