Code for submitting job on cluster

I use the following code to submit a job on a cluster, but I don't know what these code means. Can some one explain me what the following code means if possible line-by-line. #!/bin/bash #PBS -N NAME_OF_JOB #PBS -l nodes=1:ppn=20 #PBS -l matlab_user=1 #PBS -l matlab_lic=20 #PBS -l min_walltime=1:00 #PBS -q small #PBS -S /bin/bash ##PBS -V ##PBS -m abe #PBS -j oe # cd $PBS_O_WORKDIR cat $PBS_NODEFILE export PATH=/opt/software/matlabr2014a/mdcs/bin:$PATH matlab -nodisplay -r "code1" -logfile code1.log Thanks