Simply typing your name at the bottom of an electronic document does not mean it is a digital signature. The reason it is not considered this type of signature is because there is no security measure in place. Anyone else can open the document, change your signature, or modify the document. Using this type of signature adds a layer of security which prevents anyone from making changes to the document or altering your signature.
A Digital Signature Requires a Special Type of Digital Certificate
In order for a digital signature to be applied to a document, you must have a special type of digital certificate installed on your computer. There are different types of signatures available for different types of documents. Depending on which documents you want to digitally sign will determine the actual setup and how you apply the signatures to the documents.