TRL (Technology Readiness Level)

A 9-level scale used by the EU to assess the maturity of a technology. TRL 1 is basic research (principles observed), TRL 4 is lab validation, TRL 6 is demonstration in a relevant environment, and TRL 9 is a proven system in an operational environment. TRL is critical for EU funding: EIC Pathfinder targets TRL 1-4, EIC Transition covers TRL 4-6, and EIC Accelerator addresses TRL 5-9.