Hey, after learn many posts here, i have a question here. How to evaluate the quality of the link resource. for example: there are too many elements from SEO tools. like Ahrefs give me URL rank, Domain rank etc, Majesticseo showed TF,CF and so on. Does any one can give me a standard? ps: I have bought ahrefs service, can you give me a standard for ahrefs seo elements or just tell me how to evaluate in use ahrefs service. I am very sorry, English is not my native language. But I'm really want to learn seo, and everything for help will make me very grateful.