Where does the configuration block of an execution actually go in pom.xml? - maven

Question

It seems a very simple question, but something is not working right.
So given a pom.xml file I wanted to use the properties-maven-plugin. If I copy what is in the docs, meaning this code:
<project>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>properties-maven-plugin</artifactId>
<version>1.0.0</version>
<executions>
<execution>
<phase>generate-resources</phase>
<goals>
<goal>write-project-properties</goal>
</goals>
<configuration>
<outputFile>
${project.baseDir}/app.properties
</outputFile>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
And then I run using mvn properties:write-project-properties, I get an error:
Failed to execute goal org.codehaus.mojo:properties-maven-plugin:1.0.0:write-project-properties (default-cli) on project backend: The parameters 'outputFile' for goal org.codehaus.mojo:properties-maven-plugin:1.0.0:write-project-properties are missing or invalid
BUT
when I edit the code above and move the configuration right next to executions and then run the command, everything works (even though IntelliJ underlines the configuration expression with red saying properties 'child' tag should be defined.
<project>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>properties-maven-plugin</artifactId>
<version>1.0.0</version>
<executions>
<execution>
<phase>generate-resources</phase>
<goals>
<goal>write-project-properties</goal>
</goals>
</execution>
</executions>
<configuration>
<outputFile>
${project.baseDir}/app.properties
</outputFile>
</configuration>
</plugin>
</plugins>
</build>
</project>
I just randomly stumbled upon this answer here that solved this issue.
Why is this happening and where are the documentations for maven that would prevent me from spending couple hours wasting on a configuration file next time I need something?

Answer 1

The reason is as follows:
The first POM defines an execution for the Maven lifecycle together with its configuration. So it is meant to run when you call something like mvn clean install. With the configuration inside the execution, you just configured that execution (not any other execution, like the one you started from command line).
The second POM has a global configuration for the plugin goal. The execution in the POM does not matter (you can just delete it), but your command line execution will pick up this global configuration.
Does this make the behaviour more understandable?