During my Ph.D. I learned a lot in the field of signal processing. You would be surprised how much mathematic is involved when processing a signal. For example, removing noise from a signal can range from a simple filtering process up to a complex optimization problem. Here I explain topics I learned during my PhD, with many pictures and examples to make it easier to understand. I also made interactive examples so you can experiment and a feeling for how things work. Usually they involved a plot representing the concept I am explaining and the user can change parameters with sliders and see how the parameters affect the plot. The website goes in depth and breath, even covering some topics in the field of electronics.