Some Problems about System requirement of I-TASSER

In the readme.txt says like that:

4.4. System requirement:
a) x86_64 machine, Linux kernel OS
b) Perl and java compilers should be installed.
c) Basic compress and decompress package should be installed to support:
/bin/tar and /usr/bin/bunzip2.
d) If you are using cluster, job management software should support:
/opt/torque/bin/qsub and /opt/torque/bin/qstat.

But,I have no idea about the fourth(d) requirenment.
What is the meaning of "job management software" and " /opt/torque/bin/qsub and /opt/torque/bin/qstat"?

Could you help me? I hope for the reply from you soon. Thank you for your attention.