Quality Score.
Quality Score is Google’s rating of the quality and relevance of both your keywords and PPC ads. It is used to determine your cost per click (CPC) and multiplied by your maximum bid to determine your ad rank in the ad auction process.
Depends on multiple factors,
• Your Click through Rate (CTR).
• The relevance of each keyword to its ad group.
• Landing page quality and relevance.
• The relevance of your AD TEXT
• Your historical Google Ads account performance.
When more people who see your ad click it, that’s a strong indication to Google that your ads are relevant and helpful to users.

Benefits:
-
Higher ad rankings
-
Lower costs
- Strong Quality Scores lower both your cost per click & your cost per conversion

How to increase quality score?
* Keyword Research - Highly relevant keywords to add to your ppc campaigns.
* Adding Negative Keywords.
* Optimizing Landing Pages (Webpage).