A method, comprising: encoding, in a memory system, original data transmitted from a host system, according to a first type of host command (COMP CMD), to compress the original data and produce an encoding result; and writing the encoding result into a nonvolatile memory device, according to a second host command (RAM FLUSH CMD), and characterized by further comprising the step of: transmitting information about the encoding result to the host system after the encoding, in that the second host command (RAM FLUSH CMD) is transmitted from the host system based on the information about the encoding result and comprises: storage location information for the encoding result; size information for the encoding result; and logical address information to be mapped to the encoding result, and in that the encoding of the original data comprises: storing the original data transmitted from the host system in a first address area of a random access memory in the memory system, based on a first host command; reading the original data stored in the first address area and compressing the read original data; and storing the compressed data in a second address area of the random access memory, wherein the first type of host command comprises the first host command. encoding, in a memory system, original data transmitted from a host system, according to a first type of host command (COMP CMD), to compress the original data and produce an encoding result; and writing the encoding result into a nonvolatile memory device, according to a second host command (RAM FLUSH CMD), and characterized by further comprising the step of: transmitting information about the encoding result to the host system after the encoding, in that the second host command (RAM FLUSH CMD) is transmitted from the host system based on the information about the encoding result and comprises: storage location information for the encoding result; size information for the encoding result; and logical address information to be mapped to the encoding result, and in that the encoding of the original data comprises: storing the original data transmitted from the host system in a first address area of a random access memory in the memory system, based on a first host command; reading the original data stored in the first address area and compressing the read original data; and storing the compressed data in a second address area of the random access memory, wherein the first type of host command comprises the first host command. transmitting information about the encoding result to the host system after the encoding, in that the second host command (RAM FLUSH CMD) is transmitted from the host system based on the information about the encoding result and comprises: storage location information for the encoding result; size information for the encoding result; and logical address information to be mapped to the encoding result, storage location information for the encoding result; size information for the encoding result; and logical address information to be mapped to the encoding result, and in that the encoding of the original data comprises: storing the original data transmitted from the host system in a first address area of a random access memory in the memory system, based on a first host command; reading the original data stored in the first address area and compressing the read original data; and storing the compressed data in a second address area of the random access memory, wherein the first type of host command comprises the first host command. storing the original data transmitted from the host system in a first address area of a random access memory in the memory system, based on a first host command; reading the original data stored in the first address area and compressing the read original data; and storing the compressed data in a second address area of the random access memory, wherein the first type of host command comprises the first host command.