Now, both the metrics are developed by Moz and both decides the scale from 0-100 based on the backlinks, content, and traffic of the website or page . Then, what is the difference?
They relate to each other in some points. DA solely depends on the quality of your backlink pointed to your domain. While PA focus on quality content of your site and also somehow depends on the backlink.
For modern google algorithms it has small role for your SEO, however it could be good for your business because it makes your more trustworthy.