linear time-invariant systems

A linear time-invariant (LTI) system is a type of system in engineering that processes signals in a consistent way over time. "Linear" means that if you double an input, the output doubles; if you add two inputs, the output is the sum of their responses. "Time-invariant" means the system's behavior doesn’t change over time—its response to a given input is always the same. These properties make LTI systems predictable and easier to analyze, forming the foundation for many technologies like audio processing, telecommunications, and control systems.