Crud Repository is the base interface and it acts as a marker interface. JPA also provides some extra methods related to JPA such as delete records in batch and flushing data directly to a database. It provides only CRUD functions like findOne, saves, etc. JPA repository also extends the PagingAndSorting repository. 

JPA repository extends CrudRepository and PagingAndSorting repository. It inherits some finders from crud repository such as findOne, gets and removes an entity. It also provides some extra methods related to JPA such as delete records in batch, flushing data directly to a database base and methods related to pagination and sorting.

We need to extend this repository in our application and then we can access all methods which are available in these repositories. We can also add new methods using named or native queries based on business requirements.

https://www.tutorialspoint.com/difference-between-crudrepository-and-jparepository-in-java#:~:text=Crud%20Repository%20is%20the%20base,acts%20as%20a%20marker%20interface.&text=JPA%20also%20provides%20some%20extra,like%20findOne%2C%20saves%2C%20etc.&text=JPA%20repository%20also%20extends%20the%20PagingAndSorting%20repository.