Voice Assistants are the virtual Assistants that use the technique of voice recognition. This technique can provide answers to the queries of users through phone and voice recognition applications. These are nowadays used in various areas to provide proper services to the user. They are built by Artificial Intelligence. Once the user interact with the virtual assistant, then AI programming uses certain algorithms understands the input and identifies the user needs. There are different set of algorithms used by AI according to the type of the query.