1. A storage device, comprising: a nonvolatile memory device comprising a plurality of memory cells, the memory cells divided into a plurality of pages; and a controller configured to control the nonvolatile memory device, wherein the storage device is configured to collect two or more write data groups to be written to two or more pages, to simultaneously perform a common write operation with the two or more pages based on the two or more write data groups, and to sequentially perform an individual write operation with respect to each of the two or more pages based on the two or more data groups.