what is spacetime according to einstein

We can know what is the time now by the clock.We may know the time but no one knows what the time is. SO in some case it is considered as a fourth dimensions case whereas in other case other definitions are said.The time has a great effect on our day to day life. The time is greatly affected by the motion by which we are having. In our day to day life we move from one place to other with a certain motion , this motion is also affecting the time but this motion are so small that the difference in time is negligible.We might have heard the news that when a astronaut travel to earth he becomes more early then we people on earth. This happens due to the impact of motion. As the motion of rocket is very much high when it moves.
      It was Albert Einstein who researched it and connected the link of space with the time which is known as the space-time now. The time are considered as a illusion to all past,present and future movements. According to Einstein for anything to be a reality all the people should have a common reason for it but for time it is different.Life event of a person who is a retired from the job and for those who are just graduated is completely different. for those who are just graduated have a future of getting job while the person who has retired has that job as a past. How can we then say that time is not an illusion.The part of time events are only the part of a space time. By the unity of all this things the space time are formed.We are the line segments in this universe. Do we can predict the birth and death of our life. We cant but it is already predicted and we are that path not moving but the path itself. It is a very vast subject to understand but all the thing that we are connecting is only the illusion of our mind. We have been moving our mind here and there without knowing what exactly the reality is. The space itself is a illusion as they dont have a very common meaning to all of us.
      Hence Albert Einstein has put this theory of illusion to time and space on the universe to where one is connected with other.