There are two row designs: single-row bearings and double-row bearings. Most ball bearings are a single-row design, which means there is one row of bearing balls. This design works with radial and thrust loads. A double-row design has two rows of bearing balls. 

Single row ball slewing bearing are four point contact bearing, it has only one row of steel balls. They could bear axial load, radial load and tilting moment at the same time. They could bear axial load, radial load and tilting moment at the same time.