Look into the Makefile and you will see all make targets documented. Below are some of the main ones
Runs the npm install which pulls all node dependencies, creates the required RPMS SRPMS and SOURCES directories, zips up the sources and then invokes mock-build to build the actual RPM
$ make local
Runs the make target above to build the RPMs and then uses cosmos-release to publish the packages to the repo service and send the release metadata to Cosmos
$ make release