Regular License is the most common type of licensing for our WordPress themes. Regular license allows you to use item in one single domain which end user is not charged to access or use. You can acquire regular license for your own website, or if you are a developer – for one client by transferring the license to your client when the project is finished.
Extended License allows use of the item in one single end product, which you or one client may sell to end users (charge end users to access or use the end product)
For more details, please refer to the Licensing page on ThemeForest.