Glossary
Why your authority score fell: twelve terms, plainly
A score drop feels like a verdict. Most of the time it is a ratio moving because a counted number moved. These definitions help you tell the difference.
First, which score are you looking at?
Three scores circulate: Ahrefs DR, Moz DA and the 0-100 Domain Rating we compute from our own link index. They share a shape and a name, but each uses different data and a different recipe.
Our formula is public. DR is round(100 times log of (referring domains plus 1) divided by log of 20 million). So it depends on one thing only, the count of distinct domains linking to you.
That makes our number easy to explain and limited in what it says. It will not notice link quality, and it cannot see traffic.
Everything below sits on that base. When a term mentions Moz backlinks, it refers to the figures Moz publishes from its own crawl. For tracking, our monthly routine keeps one tool as the constant, and the spam page explains why a messy profile is not automatically harmful.
The twelve terms
Read in any order. Each one names a thing that can move on its own.
Referring domain
A distinct website that links to you at least once. Fifty links from one site still count as one.
Backlink
A single link from a page elsewhere to a page of yours. Our index holds about 798.5 billion of them.
Domain Rating (DR)
Our 0-100 log score based on referring-domain count. Going from 10 to 11 is cheap; from 70 to 71 needs vastly more domains.
Domain Authority (DA)
Moz's own predictive score, built from Moz's data. Moz backlinks counts and ours will differ, so never mix the two.
Anchor text
The clickable words of a link. Healthy profiles lean towards brand names and plain URLs.
Top pages
The pages on your site that draw the most links. After a migration this is where leaks hide.
Lost link
A link that existed in one snapshot and not in the next. It can be a real loss or a crawl gap.
Crawl lag
The delay between a change on the web and its appearance in an index. For us, roughly a month.
Log scale
A scale where each step needs more than the last. It is why losing ten domains shifts a small site more than a big one.
Toxic link
A marketing term from tool vendors, not a Google category. Treat any 'toxicity score' as a hint.
Manual action
A human-reviewed penalty that appears in Search Console. Algorithmic demotions carry no such notice.
Disavow
A file asking Google to ignore chosen links. It does not remove them from the web or from other tools.
The usual explanation
DR fell by 7 while traffic rose: a worked, hypothetical case
Say a site had 5,000 referring domains and lost 1,500 to a dead network. Using our formula, DR moves from 51 to 47. The page that earns the traffic may not have lost a single useful link.
- Hypothetical numbers, shown only to illustrate the log scale
- The drop of 4 points came from losing a share of cheap domains
- Check which domains left before reacting to the number
Short questions, direct answers
- Is a lower DR a ranking factor?
- No. DR is a third-party metric, not something Google uses. It is a convenient yardstick for link growth, and the real signal sits in which sites link to you and how relevant they are.
- Why do two tools show different Moz backlinks totals?
- They crawl different parts of the web at different times and use different rules for what counts. Use one tool as your constant and judge trends inside it.
- Can I raise DR quickly?
- Only by adding distinct referring domains, which takes real outreach or real content. Buying a pile of cheap ones can lift the number and put the site at risk, so we do not recommend it.