Pillow block linear ball bearings have bases with mounting holes for securing them on surfaces parallel to their shaft. They keep the object they're mounted to securely positioned to prevent misalignment, shaft deflection, and inaccurate movement. Ball bearings reduce friction, provide precise movement, and are ideal for high-speed applications like robotics, industrial printers, and testing equipment. Their rolling balls make point contact with shafts, producing less friction than plain and roller bearings.