This publication gives an introduction to applied electronics and its fields. Focus lies on electromechanics, electrical engineering and thermal management of electronic devices and systems, mathematical methods in electronics, integrated circuit and audio engineering. The subject areas of electrical network, electronic circuit, digital electronics, integrated circuit designing and packaging are discussed. Special focus is on electronic waste, electronic packaging, bioelectronics, electrochemical engineering and electrochemical cell. Contents: Introduction to Applied Electronics; Towards Understanding Basics of Applied Electronics; Focus on Electromechanics, Electrical Engineering and Thermal Management of Electronic Devices and Systems; Focus on Mathematical Methods in Electronics, Integrated Circuit and Audio Engineering; Electrical Network, Electronic Circuit, Digital Electronics, Integrated Circuit Designing and Packaging; Role of Electron Microscope, Semiconductor Device, Capacitor and Capacitance Meter; Focus of Electric Current, Electronic Design Automation and Marine Electronics; Focus on Electronic Waste, Electronic Packaging, Bioelectronics, Electrochemical Engineering and Electrochemical Cell; Focus on Electric Field Proximity Sensing, Impulse Generator, Hybrid Integrated Circuit, Macroelectronics and Nuclear Electronics; Focus on Pass Transistor Logic, Vacuum Tube, Printed Circuit Board and Multi-Chip Module; Focus on Inductor, Receiver Radio and Electronic Oscillator.