What is Maven?

I keep seeing posts and threads about Maven, and POM files, and stuff like this:

Code:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>2.2</version>
    <configuration>
        <promoteTransitiveDependencies>false</promoteTransitiveDependencies>
        <minimizeJar>true</minimizeJar>
        <filters>
            <filter>
                <artifact>*:*</artifact>
                <excludes>
                    <exclude>META-INF/*.SF</exclude>
                    <exclude>META-INF/*.DSA</exclude>
                    <exclude>META-INF/*.RSA</exclude>
                </excludes>
            </filter>
        </filters>
    </configuration>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>shade</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Can someone explain to me what Maven is? How it is used? What does it do?

Thanks in advance!

 

NonameSL
The thing you have specified is the pom.xml, it basically tells maven how to build code.
Maven is a utility used to build projects. Instead of using something like eclipse and adding an external jar, you can shade it into maven. If you do use eclipse, you know that you export your plugin and let eclipse handle it. Maven has more functions and you can control your plugin being built.