SMOTE stands for "Synthetic Minority Over-sampling Technique". It is a method to deal with imbalanced data.
SMOTE is a method to oversample unbalanced data in a typical classification problem.
The feature space for the minority class for which we want to oversample could be continuous. To then oversample, take a sample from the dataset, and consider its k nearest neighbors (in feature space). To create a synthetic data point, take the vector between one of those k neighbors, and the current data point. Multiply this vector by a random number x which lies between 0, and 1. Add this to the current data point to create the new, synthetic data point.