Depending on which certification authority issued the signature certificate, the level (quality) of the electronic signature is distinguished. Again, by "which certification authority" we mean whether it is qualified or not. If it is, then it does not matter whether it was one of the Czech ones or one of the other ones in the EU. In the Czech Republic, there are three levels of electronic signatures.

The first, highest, best quality of these are called "qualified electronic signatures". These are those that meet two conditions. They have been created by means of qualified certificates issued by, for example, one of the above certification authorities (or any other qualified certification authority from the EU). And they have been created using so-called qualified means for creating electronic signatures, which in practice are most often smart cards or tokens. Qualified signatures are obligatory for use by public authorities, so if you ever receive an official document in electronic form, it should be signed with that official's qualified electronic signature.

The second, specifically Czech, level is "recognised electronic signatures based on a qualified certificate". The name is a bit of a mouthful, which is why they are often abbreviated as "recognized electronic signatures". What they have in common with qualified signatures is that they still require a qualified certificate for electronic signature. But there is no longer a need for that qualified means. This means you can do without the smart card/token. A recognised electronic signature is needed if you, on the other hand, want to send a document electronically to the government. The authorities are legally obliged to accept a document with this type of signature. Of course, the signature is no longer responsible for the correctness of the content of the document.

The third level is the so-called "guaranteed electronic signatures". These no longer need a qualified certificate to be created. Any electronic signing certificate issued by your employer, for example, is sufficient. They are therefore not subject to the same strict rules as if you get a qualified certificate. For example, no one will ask you to prove your identity. Guaranteed electronic signatures can be used everywhere other than when communicating electronically with the government. For example, in internal company processes, in business processes between commercial companies, etc.