Defines the learning rate to apply to certain layers of a model. H2O LLM Studio applies the regular learning rate to layers without a specified learning rate.

- **Backbone**
  - H2O LLM Studio applies a different learning rate to a body of the neural network architecture. 
- **Value Head**
  - H2O LLM Studio applies a different learning rate to a value head of the neural network architecture. 

A common strategy is to apply a lower learning rate to the backbone of a model for better convergence and training stability.