Observational astronomy is based on the detection of radiation emitted by astrophysical objects. All morphological and physical information about astrophysical sources is derived from observation and analysis of the emitted radiation. Continuum radiation is a natural consequence of the principle that accelerating charges radiate. In this part of the book I will review and apply principles of electromagnetism to further our understanding of important astrophysical phenomena, demonstrating in the process that important radiation processes can be derived from the basic principle that accelerating charges radiate. To that end, I will develop the theory that describes bremsstrahlung and synchrotron radiation. A theoretical understanding of these two radiation mechanisms allows us to interpret the emission of a wide range of objects, ranging from distant radio galaxies to nearby HII regions. The specific astrophysical topics covered in this part of the book include: the radiative properties of pulsars, dispersion and Faraday rotation of electromagnetic radiation, active binary star systems, accretion disks, supernova remnants, particle acceleration, cosmic rays and active galaxies.