This thesis describes a study into the performance of both opening and closing switches, as used in pulsed-power networks. It also discusses the important energy storage and compression techniques that are used in the generation of high-energy pulsed power. Various different types of switches are involved in these applications, and particular consideration is paid to the performance of the MESS (Magnetic Energy Switching System) switch, used both in isolation and as part of a pulse-forming network. Exploding wires and foils are also investigated in some detail, since important features from the action of these are present in most opening switches.