This file contains the necessary dependencies to run a Spring Boot application. Let's review the file's content, as follows:

<?xml version="1.0" encoding="UTF-8"?>
  ...
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>Spring-boot-starter-parent</artifactId>
    <version>1.5.8.RELEASE</version>
    <relativePath/>
  </parent>
  ...
  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>Spring-boot-starter</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>Spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>
  ...
</project>

The parent pom section provides the necessary dependency and plugin management for the application.

The Spring-boot-starter dependency contains all of the dependencies that you need to get the project up and running, using a curated set of managed transitive dependencies. There are also other starters that you may want to use, depending on what you need for your project (for example, JPA, queues, security, and so on).

The Spring-boot-starter-test dependency includes the whole set of dependencies for testing. It will allow you to write not only unit tests, but integration tests as well.