What are “social, political and economic standards” for joining EU?

From Wikipedia:

On 2 March, however, Spanish foreign minister José Manuel Albares stated that "belonging to the EU is not a capricious process or one that can be done by a mere political decision", reminding that the candidate country "must meet certain social, political and economic standards"

What are specific "social, political and economic standards" for joining EU mentions here.

I don't see an answer for this matter in this question posted earlier.