How does DESelect authenticate Marketing Cloud users?

When users perform actions in DESelect, they do so in their own name. That way you maintain full
visibility and accountability on the data processing by users. For example, when a user creates a new
Data Extension in DESelect, the ‘Created By’ of this Data Extension will show the user’s name.

Authentication happens through oAuth2, which is the industry standard safe way of authentication
without sharing any passwords with DESelect and also a Salesforce best practice when building
packages for Salesforce Marketing Cloud. DESelect uses the web-app authentication method.

Note that DESelect can only be used by a Salesforce Marketing Cloud user when (s)he is logged in.
When the user logs out of Salesforce Marketing Cloud, (s)he is logged out of DESelect as well.