SQL 2017 Enterprise core Licensing


we are migrating 2012 dbs to sql 2017. customer asking whether to proceed with 2 core enterprise Licensing or more?

I am not having any idea in this regard. Can you please guide what and all things to have to keep in mind in suggesting the SQL licensing purchase? Windows server 2016 is 10 core . shall i suggest SQL 2 core enterprise licensing? or more ?

How this works actually?It is little urgent. Once i confirm the customer with 2 or more core licensing then he will purchase.

Please help.