Electronic signing vs. the old print-sign-scan routine
Printing a document, signing it by hand, scanning it back in, and re-attaching it to an email takes 10–15 minutes on a good day, and isn't even possible if you don't have a printer or scanner nearby. Electronic signing replaces the entire routine with drawing or typing a signature directly onto the digital document.
What makes it valid
Under the US ESIGN Act, the EU's eIDAS regulation, and equivalent laws in most other jurisdictions, an electronic signature carries the same legal weight as a handwritten one for the vast majority of everyday agreements — leases, contracts, consent forms — as long as it clearly reflects the signer's intent. A small set of document types (some wills, certain court filings) still require wet-ink signatures by law, so check requirements for anything unusually formal.
PrivaPDF applies the signature entirely inside your browser tab, so the document you're signing — often something containing personal or financial details — never has to be uploaded anywhere to get signed.