Theory:

The poet is talking about how he was walking down a road, and there were two different roads. He had to choose one of them. The poet says that as he was a single person, he could not travel on both roads. Yellow wood means a forest with leaves that are wearing out, and they have turned pale and yellow, and it is the season of autumn. It represents a world which is full of older people. The poet stood there for a long time and looked at the path very carefully. Before taking the path, he wanted to know how it was. He was able to see the road till from where it curved after which it was covered with trees and was not to be seen. It happens in our life also when we have choices, and we have to choose only one out of them, we take time to think about the pros and cons, whether it is suitable for us or not and only then, we decide on what path we should choose.
 
 
The poet looked at the other path and decided to go in that way. He says the path he chooses had grass on it which means that it was rarely used. Many people had not walked on this path earlier; that is why this path was of grass. After he walked on the path for some distance, he felt that the path had been worn out the same way the before one and were similar. Even in our life, we take one path or choice, but all of them have the advantages and disadvantages to face.
  
The poet says that both the paths were similar that morning. Both the paths had leaves and grass on them, and no one had stepped on them as they were still green in colour; otherwise, they would have been crushed by the foot. He thought he would take the other path for another day, although he knew that one way leads to another. He knew that he could not go back on the alternate he had taken. In the same way, in our lives, if we choose an option, we must keep on moving ahead with that option as we never get a chance to come back and take the other option that we had left earlier.
  
He says that in the future, with a deep breath he will say that long ago, he had reached a point in life that there were two options for him and he travelled on the road which had been travelled upon by few people and that decision made so much of difference. In the same way, when you are older, you will say that way back, when you were young, you had two options. The choice that you made, made you. This is a powerful message for all the students - that you should be wise and be careful while making, choosing, correct alternative out of the options that you have in your life because your future depends on the choice that you make today.