Explain the concept of auto-configuration and its role in application setup.

Auto-configuration is a mechanism that automatically configures application components based on the libraries present in the classpath and the settings. In Spring Boot, for example, auto-configuration analyzes dependencies and configuration properties to create and configure beans without the need to write a lot of explicit configuration code.

Role of auto-configuration:

• Simplifies application setup by reducing boilerplate code.
• Allows quick project startup with sensible default settings.
• Enables overriding settings when necessary, providing flexibility.

Example: if a H2 database is present in the classpath, auto-configuration will create a DataSource and configure the connection automatically.