What does -D indicate in maven command?

Question

Can anyone explain what -D indicates in maven command: mvn clean install -DskipTests

Answer 1

You define a property that can be read by a Maven Plugin or being used inside the pom.

$> mvn --help

usage: mvn [options] [] []

Options:
 ...
 -D,--define                       Define a system property
 ...

In this particular case you tell the maven-surefire-plugin to skip tests.