The Aggregation framework is a tool that helps in data analytics. It breaks down complex queries into simple ones. Aggregation operations are used to group data, perform operations on it, and analyse the changes in data over time. The analysis of the data is done using a pipeline framework such that data is passed through the documents in stages. At each stage, some operations are performed. The output of one function is the input to the next one. This continues till the output stream is produced.