Cloud and cloud-to-ground lightning is comprised of a variety of processes including the classical initial or preliminary breakdown, fast breakdown creating large-scale streamer formations, leader steps, space stems and space leaders, needle-like discharges from the lateral surface of hot leader cores, recoil leaders, return strokes, and M-components. These processes produce electromagnetic emissions that can be measured by sensors operating at different frequency ranges providing us with their wideband radio frequency waveforms, VHF and optical images, as well as energetic radiation signatures. Modeling, often constrained by observations, is performed to describe different aspects of these lightning processes. We invite scientific contributions that use observations and modeling of different lightning processes to improve our understanding of them. Results from field and laboratory experiments, theoretical work, and numerical modeling, as well as inferences from lightning locating system data are welcome.