Can't understand Bag Of Words Concept and how does it improves the prediction efficiency

[as1733]

I am a newbie i have studied a lot on data science and r programming but this is my first time implementing a R script to solve a problem it would be very kind of you if you can walk em through the feature engineering part

[karan221]

How much did you score in this problem?

[as1733]

Final score was 0.6460