I am new to Bitcoin and Blockchain and I am writing a thesis for my university about this topic.

I have a general question about digital signatures, which are needed to verify a transaction.

As far as I understood, for having a digital signature, one need to have a public verification key and a secret key.

Is the secret key equal to the private key which is needed to spend transactions.

Analog: Is the public verification key the same as the public key whose hash is the bitcoin adress ?

Thank you in advance.