A digital signature is a type of electronic signature that is encrypted. It is important to understand the differences between using a digital signature and a basic electronic signature. Your basic electronic signature does not use any form of encryption. A good example of an electronic signature is the signature you use in your email messages. Anyone can change, modify or delete this type of electronic signature. For example, anyone could copy your email message into a new message and re-sign the message using their electronic signature.
A Digital Signature Prevents People from Making Changes to Your Documents
A digital signature uses encryption to prevent other people from modifying, changing or deleting your signature. This same encryption can also be used to prevent people from copying or changing your document, email or other types of files. Only the people with the correct public key are able to open and verify the document. They may be able to revise the document, but changes can be shown by requiring the person who is modifying the document to re-sign the document using their own digitally encrypted signature when changes are made.