EnterraHost
Two jobs run on two clocks. The weekly crawl is structural and free. The monthly analysis is the full pass, it buys data from outside your site, and it is the one that spends credits.
They answer different questions, which is why having a clean weekly scan does not make the monthly analysis redundant.
What the full run adds
Search demand. Volume for the terms your pages target, so a page can be judged against what people actually search rather than against what it says it covers.
Rankings. Where you sit for those terms. A crawl can tell you a page is well built. Only a ranking tells you whether it is winning.
Backlinks. Referring domains, whether they are follow or nofollow, and a spam signal. This is the number that usually explains why a good page does nothing.
Competitors. Up to the cap on your plan, the same treatment for the domains you name, which is what turns "we should rank for this" into "they rank for it with a thinner page".
Opportunities. The terms competitors hold that you do not, which is the useful output of comparing two sites rather than an afterthought.
Where it appears
The overview counts scans and analyses separately for exactly this reason. A site with 736 scans and 19 analyses is behaving correctly, because one runs weekly and the other monthly.
Each run appears in the recent runs list with a type of SEO analysis rather than Site scan, and the score on that row is the one the monthly pass produced. Reports adds the same events to a longer history, alongside the emailed report if you have delivery turned on.
Why it spends credits
Volume, rankings, backlinks and competitor data are paid lookups. Each competitor adds roughly 80 to 140 credits to every full run, because two of the calls are per competitor. That is why the competitor cap exists per tier and why ten competitors on a small pool is a bad trade.
The weekly scan does not spend credits, because it only fetches your own pages.
What to do with it
Read it as a verdict rather than a to-do list. The scan tells you what to fix. The analysis tells you whether fixing it was enough, and it is the only place a ranking, a backlink profile and a demand figure sit beside each other.
Three things are worth looking at every month. Whether average position moved for the terms you care about. Whether referring domains grew without a spam signal growing with them. And whether the opportunity list changed shape, because a list that looks the same each month is a list nobody worked through.
Running one outside the schedule
Business and Agency can start a full check on demand rather than waiting for the month. That is the button to use after a relaunch, when waiting four weeks to find out whether the new pages rank is too slow. It spends credits in the same way as the scheduled run.
Lite and Pro receive the monthly run but cannot trigger it early, which is a limit of the pool rather than of the interface.