What you should know about item licensing:

• ‘Regular License’: you may use it only on one domain/project/theme.
• ‘Extended License’: this is 5 times the cost of the ‘Regular License’ – you may use it on as many domains/projects/themes as you wish.

So, if you wish to use a plugin on 2 websites, you must purchase 2 ‘Regular Licenses’ for it. If you wish to use it on 5 or more websites, you should purchase an ‘Extended License’.