hello every one i want to know meaning of following line

INST_PARA=$HOME/install/Install.Para
SAVEMEDIUM=`awk '$2=="ArchiveSave"{print$4}' $INST_PARA`

The first line assigns the path and name of a file to the variable INST_PARA. On the next line, awk is being used to look through each line of that file. If the 2nd ($2) item on the line is "ArchiveSave", print out the 4th ($4) item on that line. If you want to include a portion of the file $HOME/install/Install.Para I can show you what the output would be.

BTW, I believe there needs to be a space between 'print' and '$4'

thank you for replying the below line is install.para and plus if i want the output be "DVD" what i must add to this file

% Component % COM %
% Device % /dev/rStp0 %
% Host % local %
% Language % engl %
% Font % 1 %
% Screen % X11 %
% TouchScr % false %
% TimeServer % false %
% TimeClient % true %
% TextServer % -local %
% Variant % VFF %
% Verbose % true %
% Trace % false %
% ArchiveBlocks % 1900 %

The script lines you posted will set the variable SAVEMEDIUM to the value of ArchiveSave. So to have it set to DVD add the following line to Install.Para:

% ArchiveSave % DVD %

thank you very much