What is the difference between FIR and IIR filters in Digital Signal Processing (DSP)?

In DSP, FIR (Finite Impulse Response) and IIR (Infinite Impulse Response) filters are two common types of filters used for signal processing. The main difference between FIR and IIR filters lies in the nature of their impulse responses and the way they process signals.

FIR Filters:

FIR filters have a finite impulse response, which means that their output is a weighted sum of the input signal samples. These filters have a linear phase response and are often preferred for applications that require precise control over the phase of the output signal. FIR filters are known for their stability and ease of implementation.

IIR Filters:

IIR filters, on the other hand, have an infinite impulse response, which means that their output depends on both past and present input samples. These filters have a nonlinear phase response and can achieve a more compact filter design compared to FIR filters. However, IIR filters are more prone to stability issues and require careful design to prevent instability.

In summary, FIR filters have a finite impulse response and linear phase response, while IIR filters have an infinite impulse response and nonlinear phase response. The choice between FIR and IIR filters in DSP depends on the specific requirements of the application in terms of phase response, stability, and filter complexity.