Linear guides are primarily categorized into profile rail guides, plain bearing guides (such as dovetail slides), and shaft guides (often using ball bushings). Profile rail guides, which utilize recirculating ball bearings, are the most common in CNC machines and industrial robots due to their high precision, rigidity, and ability to handle heavy loads from multiple directions. In contrast, plain bearing guides offer a simpler, lower-profile design for linear motion but rely on sliding contact, making them suitable for lighter-duty applications where smooth, quiet operation is needed.