At one level, it’s simply a vector of weights. In a simple 1-of-N (or ‘one-hot’) encoding every element in the vector is associated with a word in the vocabulary. The encoding of a given word is simply the vector in which the corresponding element is set to one, and all other elements are zero. It's all about Natural Language Processing.

If you are interested in more, check out these excellent reviews by Adrian Colyer posted in The Morning Paper.

https://blog.acolyer.org/2016/04/21/the-amazing-power-of-wor...