Could you please explain the unix shell code

Hi all,

Please explain the code in detail. I have 2 sample scripts, but I didn't get clear idea about this. I am new to this shell scripting area.

1.

#!/bin/ksh
PATH=$PATH:/usr/local/bin:/users/pgp-6.5.2
WORKDIR=/users/xfercrd
export PATH WORKDIR
find $WORKDIR/archive -mtime +45 -exec rm {} \;
cp $WORKDIR/cuc.ftp $WORKDIR/cuc.ftp.save
cp $WORKDIR/ftpupload $WORKDIR/ftpupload.save
cp $WORKDIR/vaxdir $WORKDIR/vaxdir.save
$WORKDIR/bin/getdirlist
$WORKDIR/getdir > $WORKDIR/vaxdir
$WORKDIR/bin/makeqfile
$WORKDIR/cuc.ftp
PGPPASS="hardware rocket cafe"
PGPPATH=/users/cucpgp
export PGPPASS PGPPATH
$WORKDIR/bin/procftp
PGPPASS=""
export PGPPASS
cp $WORKDIR/?CUE* $WORKDIR/archive
rm $WORKDIR/S*

and 2 program is

#!/bin/ksh
# File : lbl

# Set Variables
PATH=$PATH:/usr/local/bin
WORKDIR=/users/xferexplbl
export PATH WORKDIR
dirpath='$leg'
export dirpath

# Remove Archive Files Older Than 60 Days
find $WORKDIR/archive -mtime +60 -exec rm {} \;

# Copy Old FTP Runs To A Backup
cp $WORKDIR/cuc.ftp $WORKDIR/cuc.ftp.save
cp $WORKDIR/vaxdir $WORKDIR/vaxdir.save

# FTP To Retrieve A List Of File Names To Be Picked Up
ftp  -v corp.cuc.com << EOFDIR | tee  $WORKDIR/vaxdir
cd exprpt
dir EXPSCRLBL*
quit
EOFDIR

# Create FTP Command File
$WORKDIR/bin/mkftpfile

# Execute FTP Command File
$WORKDIR/cuc.ftp

# Create Upload File, FTP Upload Command File
# And Email And Log Files
$WORKDIR/bin/mkrecord.pl

# Execute FTP Upload Command File (Copy To Production)
$WORKDIR/ftpupload

# Compress Files And Move To Archive Directory
compress $WORKDIR/EXP*
mv $WORKDIR/EXP* $WORKDIR/archive

---------------------

Why $PATH is specified in the below statement?
# Set Variables
PATH=$PATH:/usr/local/bin


Thanks
r_kar