Definition of SAP_NEW:-
SAP_NEW is a SAP standard Profile which is usually assigned to system users temporarily during an upgrade to ensure that the activities and operations of SAP users is not hindered, during the Upgrade. It contains all the necessary objects and transactions for the users to continue their work during the upgrade. It should be withdrawn once all upgrade activities is completed, and replaced with the now modified Roles as it has extensive authorizations than required.
Definition of SAP_ALL:-
SAP_ALL is a SAP standard profile, which is used on need basis, to resolve particular issues which may arise during the usage of SAP. It is used by Administrators/Developers only
SAP_NEW is used in the Production environment during a version upgrade whereas SAP_ALL shouldn't be or not allowed be used in Production (for audit purposes obviously), except where necessary, in a controlled manner with all proper approvals from the customer.