This innovative introduction to the foundations of signals, systems, and transforms emphasises discrete-time concepts, smoothing the transition towards more advanced study in Digital Signal Processing (DSP). A digital-first approach, introducing discrete-time concepts from the beginning, equips students with a firm theoretical foundation in signals and systems, while emphasising topics fundamental to understanding DSP. Continuous-time approaches are introduced in later chapters, providing students with a well-rounded understanding that maintains a strong digital emphasis. Real-world applications, including music signals, signal denoising systems, and digital communication systems, are introduced to encourage student motivation. Early introduction of core concepts in digital filtering, DFT and FFT provide a frictionless transition through to more advanced study. Over 325 end-of-chapter problems, and over 50 computational problems using Matlab. Accompanied online by solutions and code for instructors, this rigorous textbook is ideal for undergraduate students in electrical engineering studying an introductory course in signals, systems, and signal processing.