SEMrush is a very useful tool in SEO. If you have a question that how does SEMrush competitors analyses works then stay here I will explain you the whole topic.
1. SEMrush check your competitor's backlinks and analyse that which type of backlinks they have created.
2. It also focused on the competitor keywords on which they are ranking. SEMrush find out the quality of the keyword gives us related keywords.
3. SEMrush also check the whole website and guide us in the site audit.
Read here: https://getassist.mystrikingly.com/blog/what-are-semrush-s-pros-and-cons-their-features