Sentiment analysis is a process of determining whether the given emotion (text) is postivie, negative or neutral. Sentiment Analysis is useful in identifying customers emotions for a service or product. In this article we will perform sentiment analysis on restaurant reviews. VADER(Valence Aware Dictionary and sEntiment Reasoner) is a lexicon and rule-based sentiment analysis tool that is specifically attuned to sentiments expressed in social media. VADER is built on Python.