Domain authority (popularly known as Moz DA) is an indication of the backlink quality and relevance of a particular domain. It’s a number calculated on a logarithmic scale of 1 to 100. That means as you grow your domain authority, it becomes increasingly tough to move up the ladder.
It’s important to note that a higher DA is not a guarantee to rank on the top. It’s just an indication that a higher DA website has increased probability of ranking when compared to other websites in the same niche but with lower DA.
Therefore, it becomes important to analyze the DA of top ranking websites before your start with your on-page optimization. Based on the DA of your competitors, you may need to tweak your SEO strategy to outrank them.