Question: `font-size:30;`

I know there's:
`em`, `px`, `pt`, and `percent`

What does it mean when there's only a number and nothing next to it?

Is there a name for that measurement?

Also, what would `font-size:30;` be equivalent to in `px`?

Answer: 
The idea of skip-gramm is comparing words by their contexts. So we consider words equal if they appear in equal contexts. The first layer of NN represents words vector encodings (basically what is called embeddings). The second layer represents context. Every time we take just one row (Ri) of first layer (because input vector always looks like 0, ..., 0, 1, 0, ..., 0) and multiply it by all columns of second layer (Cj , j = 1..num of words) and that product will be the output of NN. We train neural network to have maximum output components Ri \* Cj if word i and j appear nearby (in the same context) often. During each cycle of training we tune only one Ri (again because of the way input vectors are chosen) and all Cj, j = 1..w. When training ends we toss the matrix of the second layer because it represents context. We use only matrix of the first layer which represents vector encoding of the words.
Weights and biases are updated here:

`_, loss_val = session.run([optimizer, loss], feed_dict=feed_dict)`

The optimizer does the following - computes the gradient and then does the update step. 

The similarity is a separate computation is called in a different location and is used to validate the results. Which happens in the following section of code:

`if step % 10000 == 0:
 sim = similarity.eval()`

The validation of the embedding relies upon the similarity embedding.