An online advertising platform developed by Google, earlier known as AdWords.
It allows businesses to create & display ads on Google’s search engine results pages & its advertising network.
Introduced in 2001, it was the first pay-per-click provider offering the concept of Quality Score, factoring in search relevancy (via click-through rate) along with a bid to determine ad position.
Being the world’s largest advertising platform, it is widely used in most countries, with notable exceptions such as China (Baidu) & Russia (Yandex).