Google Adwords’ rating of the relevance and quality of keywords used in PPC campaigns. It's a score out of 10 given by Google Ads to indicate how closely related an ad & landing page are to the keywords.These scores are largely determined by relevance of ad copy, expected click-through rate, as well as the landing page quality and relevance. Quality score is a component in determining ad auctions, so having a high score can lead to higher ad rankings at lower costs. Since Quality Score is one of the factors in Ad Rank, it can have an impact on the number of times an ad is shown and the price an advertiser pays for ads.
Google’s measurement of how relevant an advertiser’s ads are to what someone is interested in. Quality Score is based on a range of factors, including click-through-rate, relevance and landing page experience.
Quality Score is an estimate of how relevant your ads, keywords, and landing pages are to a person who sees your ad. Higher Quality Scores typically lead to lower costs and better ad positions.