Both employees and customers often use the terms digital signature and electronic signature interchangeably. A digital signature is not the same as an electronic signature, however.

Apply a Digital Signature to a PDF

The primary distinction between a digital and electronic signature

An electronic signature, sometimes confusingly called an electronic digital signature, is defined by the United States Electronic Signatures in Global and National Commerce (ESIGN) Act as «an electronic sound, symbol or process, attached to or logically associated with a contract or other record and executed or adopted by a person with the intent to sign the record.» In layman’s terms, that means signing your digital document by drawing or typing your signature, inserting an image, adding an audio clip, or similar means. There is no encryption used for these methods.

A digital signature is a process by which software uses PKI technology to embed a digital «fingerprint» into your document. When a recipient opens the document, their software uses this fingerprint to determine if the document has been altered. Digital signature processing does use encryption.

When to use

Digital signature authentication adds a significant layer of security to your document that an electronic signature alone cannot provide. Subsequently, people tend to adopt a digital signature procedure for more sensitive transactions.

Legal electronic and digital signature requirements

In most areas, the question of legality addresses electronic signatures. For example, in the U.S., an electronic signature usually is considered binding if you can show intent to sign, keep a record of the process you used to create the signature, demonstrate clear consent to do business electronically, and can retain a reproducible record of the transaction.

You thus generally do not have to apply a digital signature to a PDF or other document to have a legal transaction, but because of the added security, most companies use both.

How to Use Electronic Digital Signature Software

Electronic signature software – also referred to as electronic digital signature software, e-signature software, e-sign software, digital signature software, or document signing software – allows you to draw, type, or upload a sound or image that can serve as your legal signature in an electronic transaction. offers this type of online tool for free. Many providers’ online software also lets you encrypt a digital signature or «fingerprint» into your document when you add your electronic signature, adding security.

The basic digital signature software process

Every provider has slightly different approaches to free electronic signature software, meaning you might have vastly different interfaces or need to do more or less clicking. The general process of getting your electronic signature (and if offered, a digital signature), into your document, however, is the same:

  • Upload your file.
  • Specify who needs to sign with names and email addresses (this may be you, you and others, or just others).
  • Add signature fields.
  • Add your signature by drawing, uploading an image, typing, etc. if you are signing.
  • Send the document to your specified recipients so they can sign and send it back to you.

In most cases, free digital signature software will alert your recipients that the transaction is legally binding and ask that they click to confirm the signature.

Using an app for greater flexibility

Modern companies and clients are more mobile than ever. They need to be able to work even when a solid Internet connection isn’t available. Subsequently, many providers also offer apps you can use to sign documents from your laptop, tablet, or even your smartphone. The app, which syncs with the online service, lets you perform every step in the signing process but sending the document to your recipient offline. Then, when you have a connection again, it delivers the sign request messages or alerts the sender you’ve added your signature.