Summary:
External users are mostly approvers who are external to the organization (usually belonging to the client organization), who require access to Web TimeSheet. The access is limited, wherein the external user is only allowed to approve time and/or expenses and view specific reports. External Users have a limited sub-set of permissions and they are associated with one or more clients.
Regular time sheet users on the other hand can have different functions within the timesheet varying from the basic time entry to the complete administration of Web TimeSheet. Regular timesheet users are usually the employees of the company as against external users, who belong to client organization.