I have done research on this and still can't find a strong answer. Some soures say that when using SPSecurity.RunWithElevatedPriveleges that the code is executed as a site collection admin. Some sources say, SHAREPOINT\system. Some sources say the application pool identity running the code. Some sources say, simply, with "higher priveleges".
I have an ASP.NET web app that is using server side code (C# with the SharePoint.Microsoft.dll) to interact with SharePoint. My code is currently running under the service account that is running my application pool. There are certain times that I would like to elevate such that the user running the code has site colletion-level access, but would like to know exactly which user runs the code when using SPSecurity.RunWithElevatedPriveleges.