AdWords
AdWords is the former name of Google’s paid search marketing program, now simply known as Google Ads, the largest such program in the world and most countries, with notable exceptions such as China (Baidu) and Russia (Yandex). Introduced in 2001, AdWords was the first pay-per-click provider offering the concept of Quality Score, factoring search relevancy (via click-through rate) in along with the bid to determine ad position.