The interest in CGDE increased over the past decades, where the technique has been discussed for possible applications such as synthetic chemistry, wastewater treatment, surface modification, or nanoparticle formation. The processes during CGDE depend on the polarity of the driving electrode. Generally, during normal electrolysis (lower voltages) in aqueous electrolytes, O 2 forms at the anode via the oxygen evolution reaction and H 2 at the cathode via the hydrogen evolution reaction. During anodic CGDE, in addition to O 2 , the formation of H 2 , H 2 O 2 , and other reaction intermediates (including radicals, ions, etc.) was also observed. Species such as H 2 O 2 were found to be crucial for the degradation of organic molecules during CGDE or the modification of electrode surfaces after CGDE. Cathodic CGDE has proven to be a versatile approach for nanoparticle synthesis, either from ions within the electrolyte or by decomposing the electrode material. Aside from the polarity, the color of the plasma emission depends on the composition of the electrode and electrolyte. Over the last decades, many studies have aimed to gain more fundamental insights into the reasons for the observed phenomena, e.g., emission color, product formation, or material modification. An early work by Kellogg provides the first images of the vapor layer engulfing the electrode during anodic CGDE. Further studies provided additional insights into the physical properties of the gas evolution on electrodes at high current densities during nor-mal electrolysis at high voltages as well as the transition to CGDE during voltage increase. These studies clearly illustrate that during CGDE, the electrode is isolated from the electrolyte by a vapor layer, which increases the interfacial resistance, and the current flows through the plasma ignited in this phase. Several works provide information on the plasma's properties during CGDE, using mostly optical emission spectroscopy (OES). Limited studies, however, provide direct visual insights into the plasma within the vapor layer. Following, we provide a brief overview of studies using electrodes of various shapes. For example, Schaper et al. used shadowgraphic imaging to study the plasma ignition on a millisecond timescale for different voltages at a W rod cathode (0.5 mm diameter and 0.5 mm long) with 0.9 % NaCl in distilled water. For low voltages, individual localized sparks were observed, whereas at high voltages, the plasma covered the entire electrode. The authors denoted the observed plasma as micro-arc discharges. A longer Pt wire electrode (10 mm long, 0.5 mm diameter, and protected tip) was investigated in NaOH solutions by Saito et al., using high-speed camera imaging, revealing individual sparks for low voltages and continuous plasma for higher voltages. For a wire without tip protection, a different type of discharge was observed at the unprotected side. The same group also studied flat plate electrodes of different metals (Au, Ni, Ti, and Zn), showing a continuous glow discharge during cathodic CGDE, whose color depended on the metal substrate, indicating the presence of ions from the substrate in the plasma phase. From high-speed camera images, a non-uniform distribution of individual sparks was observed on the electrode surface. Both Stojadinović 33 et al. and Yerokhin et al. showed for cathodic and anodic CGDE, respectively, that when using metal sheet electrodes, plasma emission is preferentially located at the edge of the electrode.