What is LTI system?

An LTI (Linear Time-Invariant) system is a type of system in signal processing and control theory characterized by two key properties: linearity and time invariance. Linearity means that the system's output is directly proportional to its input, allowing for the superposition of responses. Time invariance indicates that the system's behavior and characteristics do not change over time, meaning the output response to a given input will remain consistent regardless of when the input is applied. LTI systems are widely used because they can be easily analyzed and modeled using tools like convolution and frequency domain techniques.