The Eventual consistency is a new type of database approach that has emerged in the field of NoSQL, which provides tremendous benefits over the traditional databases as it allows one to scale an application to new levels. The consistency models used by NoSQL database is explained in this paper. It elaborates how the eventually consistent data structure ensures consistency on storage system with multiple independent components which replicate data with loose coordination. The paper also discusses the eventually consistent model that ensures that all updates are applied in a consistent manner to all replicas.