# Automatic Differentiation Modes
`ad_trait` supports three primary modes of differentiation, each with its own strengths and weaknesses.
## Summary Table
| **Forward-Mode** | Exact | Very Fast | Slow | Exact |
| **Reverse-Mode** | Exact | Moderate | Very Fast | Exact |
| **Hessian AD** | Exact | Moderate | Slow | Exact |
| **Finite Differencing** | Approx | Fast | Very Slow | Low |
In the following chapters, we will explore each of these modes in detail.