This paper introduces air bearings. High-speed air bearings offer very specific advantages over other, more conventional bearing technologies. The reason use of air bearing air bearings as it avoid the traditional bearing-related problems of friction, wear, and lubricant handling, and offer distinct advantages in precision positioning and high speed applications. The use of air bearings means tool life can be greatly extended. Air bearings provide extreme radial and axial rotational precision. The factors affecting the performance of the air bearing like friction, wear, stiffness, load capacity. This paper also introduces with the types of air bearing. New air bearing products like flat bearing, air bushing, vacuum preloaded bearings, air bearing slides, radial bearing and its applications in various fields. It also discuss about the advantages and disadvantages of air bearings.