Quality Score is a metric used by Google Ads to evaluate the relevance and quality of your ads, keywords, and landing pages. It ranges from 1 to 10, with higher scores indicating better quality. A higher Quality Score can lead to lower costs per click and better ad placements. The score is determined by several factors, including the expected click-through rate, ad relevance, and landing page experience. Advertisers aim to improve their Quality Score to enhance their campaign performance and achieve better results in their online advertising efforts.