Are sitecore cookies attached to a Sitecore instance or only a single website?

Question

I have a single Sitecore instance that hosts two websites. Both websites are on the same subdomain so normal cookies can be accessed on both when created properly. But Sitecore also has these, which it creates on its own if I understand correctly:

SC_ANALYTICS_GLOBAL_COOKIE

SC_ANALYTICS_SESSION_COOKIE

This question discusses what each does. What I am curious about is if each do their respective jobs on a single website within an instance of Sitecore or across the entire Sitecore instance despite the number of websites.

For Example:

Website A and Website B are both on the same instance of Sitecore.

A user visits Website A and then visits Website B.

Will the Sitecore cookies 'remember' the user as if they have visited Website B previously just because they have previously visited a website on the same Sitecore instance?

Or does Website B have no idea that a user went to Website A and both websites act as completely different entities despite their backend being hosted on the same Sitecore instance?

Answer 1

From what I understand, the SC_ANALYTICS_GLOBAL_COOKIE will be the same. However the SC_ANALYTICS_SESSION_COOKIE is per browser session based, so this will be different. Thus based on this the actual answer is:

Website B visitor and Website A visitor entries in Visitor table will be exclusive, i.e. Website B have no idea that a user went to Website A and both websites act as completely different entities despite their backend being hosted on the same Sitecore instance?

Answer 2

While Sitecore 6 has OMS and DMS which are a bit different in what is tracked and how the cookies are created, for simplicity sake, what is important to note is that in both cases this is session driven which means that the hostname is part of the information. A single user going to a different hostname..even on the same Sitecore instance will always have a different tracking cookie.. one for each site.