Need some explanation about these lines.

[Raheel Hassan]

Hello,

I have seen some Perl scripts where some times these lines are mentioned in
the begining of the script can any body explain these lines.

*Script-1*
use DBI;                                 # What is been called here.
use Test::DB::DBAccess;
use Test::DB::DBOps;

*Script-2*
package DBAccess;

BEGIN                                           #What operation is been
performed by Begin
{
unshift  @INC, "/home/LIBS";          #What is the role of unshift and @INC
unshift  @INC, "libdata/perl5/site_perl";
}


Regards,
Raheel