The GlideUser class is available to client scripts as the g_user object, which is initialized to the current user that's signed in.
The GlideUser client-side API gives you easy access to determining certain details about the user, including the user's name, roles, sys_id, and a method for getting access to client data set via the putClientData() API on the server.
The GlideUser (g_user) API is particularly useful because it eliminates the need to execute client-side GlideRecord queries, which are costly in terms of performance or slow in terms of execution time.
