The software pool is ready to be used under a version control system called environmental modules. This allows to have several versions of the same software package installed in parallel and is made for a user friendly activation and deactivation of software. "loading a module" is synonymous for "making software accessable". The most important commands to know are:
module avail
module help <package>/<version>
module load <package>/<version>
module unload <package>/<version>Loading a module manipulates the shell environment to make software visible for shell commands. Note, these changes of environmental variables are fully reversible and are taken back, if a module is unloaded.
Loading a module adds the path to the binaries of a software package to PATH. This makes executables of software packages visible. This way you may select a compiler version.
The modified environmental variables can be used by compilers, linkers, make, cmake or private software installation tools, to recognise details of installed libraries and link them accordingly. Typical examples are PATH, LD_RUNPATH, LD_LIBRARY_PATH or PKG_CONFIG_PATH.
To see, how a package is installed and which environmental variables are delivered, use
module show <package>/<version>
To learn more, please read the Modules home page 
.