Laser cooling allows one to slow atoms to roughly the speed of a mosquito and to control their motions with unprecedented precision. This elegant technique, whereby atoms, molecules, and even microscopic beads of glass, can be trapped in small regions of free space by beams of light and subsequently moved at will using other beams, has revolutionized many areas of physics. In particular, it provides a useful research tool for the study of individual atoms, for investigating the details of chemical reactions, and even for the study of atomic motion in the quantum domain. This text begins with a review of the relevant aspects of quantum mechanics; it then turns to the electromagnetic interactions involved in slowing and trapping atoms, in both magnetic and optical traps. The concluding chapters discuss a broad range of applications, including atomic clocks, studies of ultra-cold collision processes, diffraction and interference of atomic beams, optical lattices, and Bose-Einstein condensation. The book is intended for advanced undergraduates and beginning graduate students who have some basic knowledge of optics and quantum mechanics. An extensive bibliography provides access to the current research literature.