The software pool is ready to be used under a version control system called environment modules. It is made for a user friendly activation and deactivation of software and allows to have several versions of the same software package installed in parallel at non-default places. "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 adds the path to the binaries of a software package to PATH. This makes executables of software packages visible.
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.
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 
.