Stirring is widely used in the chemical, pharmaceutical, and food industries. The essential stirring operations involve homogenizing miscible liquids, enhancing heat transfer between the liquid and the heat transfer surface, as well as mass transfer in multiphase systems, suspending solid particles in liquids, and dispersing immiscible liquids. Initially, the general aspects of stirring are discussed, such as stirring equipment, mechanical stress during stirring, stirring performance, flow, and turbulence, along with a brief introduction to rheology, dimensional analysis, and model transfer. All relevant aspects of stirring technology are then discussed in detail, emphasizing that each stirring technology aspect is addressed comprehensively.