Sentinel 2 Level 1C and Level 2A

Hello everyone, I have a question. what’s the difference between L1C and L2A sentinel products. i need to estimate the woody biomass of an area from sentinel. i have a L1C and L2A sentinel image. i need to do index calculations and other calculations on the images. Which product used between the two products and why? I need your skills. Thank you

Please use the search function: Clarification on difference between L1C and L2A data