Definition of a system. Linear, non-linear and complex systems. Signal theory and information theory. Abstraction of physical quantities and event horizon. Definitions and classifications of signals. Analytical and statistical parameters of signals. Characterization of some specific types of quasi-deterministic signals. Characterization of stochastic signals. Operation regimes of measurement and information systems. Excitation and response. Spectrum of a signal. Time-frequency transformations. Analysis of systems and signals in time and frequency domains. Signal processing and conditioning for the purpose of measurement. Analogue filters. Digital signals. Sampling, quantization and coding. Characterization of digital signals. Information and measures for quantities of information. Digital measurement systems. Analysis and processing of digital signals. Digital filters. Analogue and digital signal generators.