Datastore is a place/way to store all the data you would need for your kapps and services.

Some great advantages to datastore:

• Each datastore can have its own set of fields, field names, field types, and requirements. This allows the data stored to be used and displayed/managed exactly as needed.
• You can have as many datastores as needed.
• Each datastore can have its own permissions. This allows owners of a particular service to manage the data used in that service without having access to all data.