Popular SEO Tools
Regarding tools, most of the good ones require payment however the standard are both ahrefs and semrush – both have a free version but can get expensive when using a paid version.
There are two ‘industry standard’ methods to check the quality of a link – the referring page DA or DR.. they aim to measure the same thing but developed by different companies, so differ occasionally. We go further and look at who the page links to, as sites that link top sites are looked upon more favorably.. ie they have higher ranking power that is not reflected in DA or DR.
Simply because Google does not want people to know too much about how it ranks sites, to discourage manipulating their rankings.
Some popular SEO Tools include