Do you mean they will map the words to vectors? Yes, they do, but it’s different than some methods like word2veq; I am not sure about Doc2Vec, though. For example, in word2veq, we give each word only one vector, and that’s it. This is not ideal since some words have different meanings in different contexts; for example, we have banks where we go to deposit or withdraw money, and we have river banks. Word2vec will give both banks the same vector, but in BERT, the vector is based on the context.