Simplify database access with Spring Data and secure your application with Spring Security.
Spring Boot starters make it easy to integrate other powerful Spring projects into your application. Two of the most essential are Spring Data and Spring Security. Spring Data's mission is to make it easier to work with data access technologies. The Spring Data JPA module, in particular, dramatically simplifies the creation of a data access layer. You start by defining an interface that extends `JpaRepository<EntityType, IdType>`. By doing this, you automatically get a full set of CRUD (Create, Read, Update, Delete) methods for your entity without writing any implementation code. Spring Data generates the implementation for you at runtime. You can also define custom query methods just by declaring their signature in the interface, for example, `List<User> findByLastName(String lastName);`. Spring Data will parse the method name and create the appropriate database query for you. This removes a massive amount of boilerplate code associated with JDBC or even standard JPA. Spring Security is the de facto standard for securing Spring-based applications. It is a powerful and highly customizable framework that handles authentication (who are you?) and authorization (what are you allowed to do?). It provides comprehensive support for various authentication mechanisms like form-based login, basic authentication, and OAuth2. You can configure it to define access control rules for your web endpoints, for example, specifying that only users with an 'ADMIN' role can access URLs under `/admin/**`. Spring Security integrates deeply with the Spring framework to protect your application from common security threats.