What_is_Cloud.txt

https://github.com/JEONSIEUN/HSU2014SW/commit/906f6ca98611b71995b3f726a780f51a6733891c
https://github.com/JEONSIEUN/HSU2014SW/commit/c1df36cc3e80324b9dc4abbb11d58501323744b
https://github.com/JEONSIEUN/HSU2014SW/commit/9b5d0f4e4bac05c3cf2cd63143495ae4b54f6b6
https://github.com/JEONSIEUN/HSU2014SW/commit/bb202dbfcdbc145fe2135421763484b4b71c70bcc6