When you first launch a website, you will more than likely start with a shared host. This type of hosting means that the same server has multiple users and each user has a certain amount of bandwidth.
For those who are just starting out or have a small website, this is usually the default choice, as it is the easiest and most cost effective solution.
The downside to shared hosting is that it is, well, shared. There is little room on a server, which means you may experience slower performance depending on what other hosted sites are doing. There is also an increased security risk, as a hacker could gain access to multiple sites.
Eventually, you will probably start to feel the constraints of shared hosting, which will prevent high traffic sites from performing at peak performance.
Cloud hosting supports these issues because users are supported by several different servers. Moving to a cloud host means that high traffic sites will still operate with consistent reliability.
Since you are no longer confined to a single server, there is no limit to the number of users who can scale and grow.
Cloud hosting allows high traffic websites and applications to avoid downtime, errors, or slow page loading. If one server goes offline, another will instantly recover your site and keep it running smoothly.
Cloud hosting also offers increased security, as your files will be evenly distributed across a variety of servers and not stored in one place.