AdWords
AdWords is Google’s proprietary advertising platform. It is the largest platform in the world and is responsible for the majority of Alphabet’s revenue. The most common way to advertise on this platform is with a search ad that shows on Google’s search engine, but there are many other forms of advertising you can do with AdWords such as showing an advertisement on a website or on Gmail. AdWords is known for innovating the discipline of keyword bidding, which revolutionized online advertising by allowing advertisements to be purchased by a free market auction.
Read Google’s definition.