The "cloud plan" is likely to trigger a new round of information technology revolution and have a profound impact on the international situation. Simply put, "cloud" is the use of Internet technology for remote computing and data storage. As long as the user has one that can access the Internet Ordinary computers or mobile phones can perform complex calculations, and personal data can also be easily stored in the "cloud" through the Internet for storage. From a hardware perspective, the "cloud" is a group of computers, each of which includes hundreds of thousands of units, and even Millions of computers, which may be high-performance servers, or ordinary computers connected to the Internet, or even mobile phones. According to the above text, what is the most accurate understanding of the "cloud"? ['"Cloud" is a computer cluster of hundreds of thousands or even millions.', 'Without the Internet, the "cloud" function will not be realized.', '"Cloud" technology is actually Internet technology.', 'Who controls the "cloud", who controls the virtual world.']