## Outline For Learning About The DFT and FFT

Here is an outline of the steps used to explain both the **DFT and FFT**.

- First the
**DFT** will be explained. This is the vital first step, since an FFT is a DFT and there are, therefore, basic concepts in common with both. Learning this first will make understanding the FFT easier.
- Once you understand the basic concepts of a DFT, the
**FFT** will be explained. This is broken into several steps.
- The "
**Danielson-Lanczos Lemma**"
will be explained, which is the first step to understanding the FFT.
- The "
**twiddle factor**" will be explained, which is another key to understanding the FFT.
- The "
**Butterfly Diagram**" will be explained. The Butterfly is an FFT in diagram form. It's the final step of this tutorial and builds on the prior concepts.
- Several examples will be given along with the basic concepts above.