What is Doorway pages?

[alexmt0]

Doorway pages are the check-fraud of SEO. Spin up hundreds of near-identical pages per city/keyword combo, stuff them with LSI garbage, redirect the whole herd to one money page. It's cloaking's lazy cousin.
Webspam teams eat this for breakfast, expect a manual action, tanked SERP rankings, nuked domain reputation. Anyone still peddling this is either clueless or scamming clients.