it is promotional code provided by google time to time to its customers. you can save adwords expanses by using adwords coupons. Google offers Coupon worth Rs. 2000 in India and across the globe for new users who register the first time. Adwords coupons are basically token credit given to an Adwords user. This coupon is to be used with an account which hasn’t used a coupon yet. Google’s way of enticing businesses to try out their Google Ads. They could be new users who want to try google adwords or agencies who want to offer trial runs to prospective clients. Generally, you get a $50–$150 credit that can be used to run Pay Per Click ads on Google.
Once this credit is done, you can either stop running ads, or pay for them yourself.