If you are hosting a Drupal website on OIT Web Hosting, you can SSH into your host, but you cannot run the command-line tool Drush from your SSH session because OIT doesn't allow PHP to be run directly from the SSH command line of Web Hosting accounts. However, this doesn't mean that you cannot use Drush at all with OIT Web Hosting – you just have to work around this limitation.
If you have to perform module updates on your Drupal site, then Drush is the way to go. Drush will help you to update all modules on your site(s) quickly and painlessly.
Drush has many commands and options. These commands need to be run from the directory where the settings.php file for your site is, i.e.
/path/to/drupal/sites/default
Drush (Drupal Shell) is a great Drupal "module" to accomplish many administrative tasks via the command-line. It is not a module in the normal sense, because it's not enabled/disabled from the Drupal admin. Instead, it actually lives anywhere on your local system and is run like any other local executable. Here are some of its key features from the Drush Drupal.org page:
A few core drush features:
