Resolving "What is casino license?" takes one visit to a public register. A licence number printed in a casino site's footer is a claim, and the licensing authority's public register is where the claim is checked. The register shows the company that holds the licence, its status and often the domains it covers. A match on all three takes a few minutes and says far more about a casino than any badge or rating.
A licence badge in a footer ought to open the matching register entry on the authority's own website, and a badge that opens a page on the casino's domain shows nothing. A licence also covers particular products, so a site licensed for casino games may lack cover for the sports betting or lotteries it also sells. The scope is part of the register entry, and it takes a moment to read next to the status.
A licence can be active, suspended, surrendered or revoked, and the register usually says which. A suspended licence may still appear in a footer for weeks, since nothing forces a site to update its own badge. Some registers also publish sanctions and conditions placed on a licence holder, which show how the company has behaved in the past. A recent sanction for complaint handling or unfair terms tells a player what to expect from that operator.
Every licensing authority keeps a public register of the companies it licenses. Searching it by the licence number or the company name shown on the casino site should return a single entry, with the same company, an active status and, on many registers, a list of approved domains. A number that returns nothing, a different company or a domain missing from the list is a reason to stop before any deposit.
Sites often run on a platform company that holds the licence for them; the name in the terms should match the register exactly, and a mismatch deserves a written answer.
Nothing on its own. The number is a claim, and the licensing authority's public register is where that claim gets checked.
Active, suspended, surrendered or revoked. A suspended licence may still appear in a footer for weeks, since nothing forces a site to update its badge.
To the matching register entry on the authority's own website; a badge that opens a page on the casino's domain shows nothing at all.