Sometimes you may need to disable the script execution in certain directory for the security reasons.
If you are using Apache web server, you can disable it using .htaccess. You just need to add the following code to disable the execution:
AddHandler cgi-script .php .pl .py .jsp .asp .htm .shtml .sh .cgi
It is recommended that you disable the script execution for your upload, images etc. (where there is no script execution is required). This is improve the security of your website.