Persist data in memory only in deserialized format Persist data in memory and if enough memory is not available evicted blocks will be stored on disk Same as MEMORY_ONLY but difference being it persists in serialized format. This is generally more space-efficient than deserialized format, but more CPU-intensive to read. Same as MEMORY_AND_DISK storage level difference being it persists in serialized format Persist the data partitions only on diskSame as the levels above, but replicate each partition on two cluster nodes Similar to MEMORY_ONLY_SER, but store the data in off-heap memory. This requires off-heap memory to be enabledDefault: NONE