The command

mvn install:install-file \
  -Dfile=<path-to-file> \
  -DgroupId=<group-id> \
  -DartifactId=<artifact-id> \
  -Dversion=<version> \

Why we need it

Not every JAR is available on Maven repositories by default. That makes sense since not every JAR is made to be public. However, if a JAR is required to compile your project, it might be necessary to add this JAR to your local repository.

More details can be found on this Guide to installing 3rd party JARs.