What is the difference between a qualified and non-qualified certificate?

Qualified certificate – a qualified electronic signature that is legally equivalent to a handwritten signature. You can use it wherever its use is permitted.

Non-qualified certificate – an electronic signature verified using a non-qualified certificate has the same legal effect as a handwritten signature only if both parties have previously entered into an agreement containing provisions for the mutual recognition of signatures verified using a non-qualified certificate. A non-qualified certificate can be used to encrypt and sign documents and, for example, email messages.