A storage device includes a plurality of nonvolatile memory devices; and a controller connected in common to the plurality of nonvolatile memory devices through data lines, the controller being configured to detect first offset information by performing a first training operation with respect to a first nonvolatile memory device from among the plurality of nonvolatile memory devices, the controller being further configured to, based on the first offset information, perform a second training operation with respect to a second nonvolatile memory device from among the plurality of nonvolatile memory devices.