# Component Types¶

Deriving from Sympl, most components in climt are either TendencyComponent, DiagnosticComponent, ImplicitTendencyComponent or Stepper.

• TendencyComponent takes the model state as input and returns tendencies and optional diagnostics. A radiation component is a good example of such components: any radiation component returns the heating rate of each layer of the atmosphere (in $$degK/s$$)
• DiagnosticComponent takes the model state as input and returns some other diagnostic quantities. An example would be a component that takes the model state and returns the optical depth.
• Stepper takes the model state, and returns new values for some some quantities in the model state. A dynamical core is a good example, which returns new values of winds, temperature and pressure.
• ImplicitTendencyComponent takes the model state and outputs tendencies (like a TendencyComponent) but require the model timestep (like a Stepper) for various reasons, including to ensure that a vertical CFL criterion is met.