An electronic signature software helps customers sign documents digitally. As long as the legal requirements are met, an electronic signature can be just as or sometimes even more binding than a handwritten signature.
The legal basis for this in the European Union is the eIDAS Regulation. In Switzerland, the ZertES law provides a similar legal basis.
Electronic signatures can have different levels of security.
Simple electronic signature (SES)
The SES is the lowest level of electronic signature. It is similar to inserting a scan of a handwritten signature into a PDF or putting your name at the end of an email.
Advanced electronic signature (AES)
The signing person must be identifiable and it must not be possible to detect if the document has been modified after signing.
Qualified electronic signature (QES)
An electronic signature with this high level of security is the digital equivalent to a handwritten signature. This type of signature may only be issued by special trust service providers.
This category contains services from companies based in a member state of the European Union (EU), the European Economic Area (EEA) and the European Free Trade Association (EFTA).
You can read more about the listing criteria here.