3GPP 23.501 v20.2.0 — the document's own text
5.7.3.2 Resource Type
Taught in 14. What the network promises (The 5G system architecture, in depth), 5. The connection, and what is promised on it (The 5G system architecture, overview).
The resource type determines if dedicated network resources related to a QoS Flow-level Guaranteed Flow Bit Rate (GFBR) value are permanently allocated (e.g. by an admission control function in a radio base station).
GBR QoS Flows are therefore typically authorized "on demand" which requires dynamic policy and charging control. A GBR QoS Flow uses either the GBR resource type or the Delay-critical GBR resource type. The definition of PDB and PER are different for GBR and Delay-critical GBR resource types and the MDBV parameter applies only to the Delay-critical GBR resource type.
A Non-GBR QoS Flow may be pre-authorized through static policy and charging control. A Non-GBR QoS Flow uses only the Non-GBR resource type.