This lecture provides an introductory lesson on signals and systems, covering the purpose of the course, course content, and examples of signal processing. It delves into the characterization of continuous linear systems, Fourier analysis, and discrete signal modeling. The lecture also explores signal classification, mathematical representations, and the concept of signals in various physical mediums. Additionally, it discusses convolution operators, differential equations, and the design of linear systems. Practical applications such as image processing, compression, and multimedia are also addressed.