Keywords can be either campaign identification or action words that are used for 2-Way SMS communications in Dedicated or Shared Short Code campaigns.
When an action keyword is texted/sent by the mobile end-users handset to a short code number (example: Text HELP to 30838) the mobile end-users handset will receive on their phone the auto-response you have set up for this mandatory action keyword, your database will be automatically be updated if necessary.
When a campaign identification keyword is texted/sent by the mobile end-users handset to a short code number (example: Text TNT1 to 30838) the mobile end-users handset will receive on their phone the auto-response you have set up for that Keyword.