quangngoc It identifies the occurrence of words in a document. It identifies the vocabulary and the presence of known words. Hence, it is very simple and flexible. It is intuitive that documents consisting of similar content will be similar in other ways such as meaning too. So, the BoW process will create a simple and quick group of features which can be used. The BoW model can be made as simple, and as complicated as possible. The main difference is how the vocabulary of words is maintained, and how the different words are scored.