  Storage rings have been employed over three decades in various kinds of
nuclear and atomic physics experiments with highly charged ions. Storage ring
operation and precision physics experiments benefit from the availability of
beam cooling which is common to nearly all facilities. The basic aspects of the
storage ring components and the operation of the ring in various ion-optical
modes as well as the achievable beam conditions are described. Ion storage
rings offer unparalleled capabilities for high precision experiments with
stable and radioactive beams. The versatile techniques and methods for beam
manipulations allow for preparing beams of highest quality at any energy of
interest. The rings are therefore part of the experiment . Recent experiments
conducted in a wide energy range and with various experimental installations
are discussed. An overview of active and planned facilities, new experimental
set-ups and proposed physics experiments completes this review.
