Electronic signature and digital signature are not the same thing

Level one: a drawing

You draw your name with a finger and it is placed on the page. Nothing about the file records who drew it, and nothing stops the page being edited afterwards. This is an electronic signature in the loosest sense: evidence of intent, worth exactly as much as the surrounding circumstances make it worth.

For most day-to-day paperwork between people who already know each other, that is enough, and everybody involved knows it.

Level two: a cryptographic signature with your own certificate

A PKCS#7 signature embeds a cryptographic hash of the document. Change one byte afterwards and the signature breaks — any PDF reader will say so. That is a real guarantee, and it is a guarantee about the file, not about you.

If the certificate is one you generated yourself, nobody has checked who you are. You have proved the document has not changed since it was signed by the holder of that key. Who holds that key is your word.

Level three: a certificate issued to you

An authority verifies your identity and issues a certificate that says so. Now the signature carries both guarantees: the file is unaltered, and a third party has vouched for the name on it. This is what regulations usually mean when they ask for a digital signature, and it is the level that costs money and takes paperwork.

Which one you need

Not a question anyone can answer in general. It depends on the document, the counterparty and the jurisdiction — in Vietnam, e-invoices and many filings require a certificate from a licensed provider, and nothing you generate yourself will substitute. Ask before you rely on it, not after.

ToolGo's PDF signer does levels one and two. It does not issue certificates and does not replace a licensed provider.