chmod is a Unix / Linux command that lets you tell the system how much (or little) access it should permit to a file.
If value is 4, then read permission is given to the file.
If value is 2, then write permission is given to the file.
If value is 1, then execute permission is given to the file.
<!-- hscripts.com javascript Check-mode calculator script -->
<script type="text/javascript" src="hcheckmodcalc/chkmodecalc.js"> </script>
<!-- End of hscripts Check-mode calculator Script -->