Metadata compatibility

Hi Guys,

Im working on a project witch will use metadatas too. It would be useful that my metadatas would be compatible with verifing metod of this site: (here is an expamle of metadatas)

https://bi.stakepoolcentral.com/tx_metadata_details?tx_hash=f22405e92625c2f637c1123fed70d095134905977f262f94d5144303ca63f3ad&key=0&query=baia

I dont understand the correlation between public key, data hash and signature. What is this signature and where is comming from? I assume that signature = secret key + data hash but how is signature created? with a cardano-cli command or … ?

Thank you
Macracanta