What is claimed is:1. A memory device comprising:an enclosure assembly comprising a first enclosure located at the top and a second enclosure located at the bottom; anda memory module disposed within the enclosure assembly,wherein the memory module comprises a module board configured with a plurality of non-volatile memory chips, a memory controller, a memory connector, and a plurality of module fastening holes,wherein the memory connector protrudes outward in a first direction from a first short side of the module board,wherein the first enclosure comprises a first main cover that covers upper faces of the module board and the second enclosure comprises a second main cover which at least partially covers a lower face of the module board,wherein at least one clamping hole penetrates the first main cover at a position overlapping the memory connector, and has a space for a hook of a host connector when the memory device is connected to a host device,wherein the first enclosure comprises only three inter-device fastening pillars, each including a fixed hole extending through the inter-device fastening pillar and the first main cover, andwherein ends of the fixed holes are open at the end portions of the inter-device fastening pillars and opposite ends of the fixed holes are open on an upper face of the first main cover.2. The memory device of claim 1, wherein the inter-device fastening pillars are located at a first, second and third corner of the memory module, respectively.3. The memory device of claim 2, wherein the memory module further comprises a module fastening hole at a fourth corner of the memory module and is spaced apart from the first short side in the first direction more than the module fastening hole placed at the first corner.4. The memory device of claim 1, wherein the memory device has a long type dimensional standard having a long side length of 119 mm, a short side length of 36.5 mm, and a height of 9.5 mm.5. The memory device of claim 1, wherein the memory device has a short type dimensional standard having a long side length of 52 mm, a short side length of 36.5 mm, and a height of 9.5 mm.6. The memory device of claim 4, wherein the long type dimensional standard has tolerances within 5% of each dimension.7. The memory device of claim 5, wherein the short type dimensional standard has tolerances within 5% of each dimension.8. The memory device of claim 1, wherein the second enclosure comprises a coupling hole that overlaps the module fastening hole, and wherein the first enclosure comprises a coupling groove in communication with the module fastening hole and the coupling hole.9. The memory device of claim 8, further comprising:a fastener that penetrates the coupling hole of the second enclosure and the module fastening hole from a lower part of the second main cover, and that is inserted into the coupling groove.10. The memory device of claim 1, wherein the first main cover comprises a first base part and a first fin protruding outward from the first base part.11. The memory device of claim 10, wherein the second main cover further comprises a second fin protruding outward from the flat plate.12. The memory device of claim 1, wherein a first side cover of the first main cover extends downward from a first long side of the first main cover, a second side cover of the first main cover extends downward from a second short side of the first main cover, and a third side cover of the first main cover extends downward from a second long side of the first main cover.13. The memory device of claim 1, wherein the second main cover is a flat plate comprising an inner surface, and wherein a free end of the first side cover, a free end of the second side cover, and a free end of the third side cover each are in overlying face to face contact with the inner surface of the second main cover.
