Training
LoRA
LoRA learns low-rank update matrices while keeping the original model weights frozen.
How it works
A weight update is represented as the product of two small matrices. This reduces trainable parameters and optimizer state while preserving the base model.
A concrete example
Illustrative: a 4,096×4,096 update at rank 16 uses 131,072 trainable values instead of 16,777,216.
Do not confuse it with Adapter layer
LoRA modifies weight updates through low-rank factors; adapters insert new network modules.