DA is a MOZ metric and stands for Domain Authority. Domain Authority is a search engine ranking score (SERS) developed by SEO software company Moz, which estimates how well your website is working and provides a rating score from 1-100.
Higher the score, higher is the ranking of your website in search engines and more organic traffic your website will get. Domain Authority or DA is a very important factor in SEO. Domain Authority is different for different websites.
For beginners, the website gets rank between 10-20 after 4-6 months. Gradually, as the domain gets old, its DA increases. For a good domain authority, you should focus on getting higher DA than your competitors as domain authority is best used as a comparative metric.