What is a security context?
The security context includes information about safe network IDs and IP addresses that are able to access the system.
The security context holds a list of all users and their encrypted passwords in memory and a list of resources that users are able to access.
The security context includes details of the principal currently using the app, which is stored by default in a ThreadLocal in an Authentication object.
ThreadLocal
Authentication
The security context includes information about permissions on the local file system describing how local file resources can be accessed.