Crawl Order controls how the crawl determines what to crawl next.
Breadth-first Search means that Yioop first crawls the seeds sites, followed by those
sites directly linked to the seed site, followed by those directly linked to sites directly linked
to seed sites, etc.
Host Budgeting means Yioop chooses what to crawl next based on a score
involving the number of pages it has already crawled from each host in the urls in the to crawl list.