Skip-gram Word2Vec is an architecture for computing word embeddings. Instead of using surrounding words to predict the center word, as with CBow Word2Vec, Skip-gram Word2Vec uses the central word to predict the surrounding words.

The skip-gram objective function sums the log probabilities of the surrounding $n$ words to the left and right of the target word $w_{t}$ to produce the following objective:

$$J_\theta = \frac{1}{T}\sum^{T}_{t=1}\sum_{-n\leq{j}\leq{n}, \neq{0}}\log{p}\left(w_{j+1}\mid{w_{t}}\right)$$