There are two very different things people call "signing a PDF", and mixing them up causes real problems.
A visual signature is your handwritten mark placed on the page — drawn with a mouse or finger, or typed in a script font. For everyday paperwork — rental forms, permission slips, internal approvals, freelance contracts between parties who trust each other — this is exactly what's expected. Kameleo's Sign tool does this entirely on your device: draw or type, drag into place, download.
A cryptographic digital signature embeds a certificate that proves who signed and that the document hasn't changed since. Some jurisdictions and industries (EU qualified signatures, certain government filings) require this level. It needs an identity-verified certificate from a trust provider — no purely in-browser tool can conjure that.
If the other party sent you a PDF and said "sign and send it back", a visual signature is almost always what they mean. If a regulation names eIDAS, QES, or "advanced electronic signature", you need a certificate-based service. When in doubt for high-stakes contracts, ask the counterparty.
Your signature is biometric-adjacent data. Kameleo never uploads it — the pad, the placement and the final PDF all stay in your browser.