Impinging jets are well known for their high heat/mass transfer rates, widely employed in industrial cooling and drying processes and as such have been investigated extensively. The present paper provides a comprehensive description of laminar free-surface and submerged impinging jets by summarizing the understanding gained in recent studies by the authors. In a previous study, a correlation was formulated for free-surface and submerged jets. However, the validity of the correlation was limited to idealized conditions, e.g. the absence of vortices. This paper experimentally and numerically examines the flow field of submerged jets under the presence of low amplitude perturbations, showing different types of vortex structures and mechanisms of jet breakup.