Standard licences are one credit, always. Templates are also one credit, even that they come with an enhanced licence. As for the other assets and licences, it depends on your subscription, what kind of assets you can license for how many credits. You see that with the subscription:

(maybe Adobe needs to update the information here, as I doubt that they mean 4k videos. They didn't touch this when they also added 4k videos to the plans, so that is unclear. @EvilBug1 can enlighten me here.)
If you ask especially for credit packs:
An extended licence is 8 credits. CREDIT PACKS cedits - Extended Licence
All other use cases are to be found on the Adobe website (I don't understand why they did not add the extended licence here either): https://stock.adobe.com/plans

See also here: https://community.adobe.com/t5/stock-discussions/stock-faq-what-are-credit-packs/td-p/9633021