The cookie_consent_silktide is a plugin used to offer users a way to know about your rules in regard to cookies. What you do with them. How you use the data and how long you keep it, etc.
Note that contrary to many websites, Snap! strives in reusing the exact same cookie for everything. This is why the cookie itself does not really define how the data is kept in the Snap! system and various modules have access to various data that some users may be sensitive about.