What is the difference between a physical machine and a cloud server

As we all know, servers have independent servers (physical machines) and cloud servers/virtual private networks (virtual machines), so which independent server (physical machine) is more suitable as a high-security server than cloud server virtual private networks (virtual machines)?
First, let's talk about cloud servers. Cloud servers unify many physical machines on the cloud platform through technology, divide them into independent cloud servers through virtual partitions, and then assign IPs to customers.
This results in that when one of the IPs is overly attacked, the entire cloud platform will be affected. This is why when a customer is attacked, many cloud server providers have to suspend the customer’s IP use, because this is necessary to ensure normal use by other customers of.
In fact, as early as the beginning, cloud servers did not develop rapidly. They are mainly independent servers (physical machines). Later, when the cloud server was developed, we also wanted to combine the cloud server to provide high-security services, but after practice, at least under the current technology, the cloud server is still not suitable for high-security servers.
The cloud server is a virtual partition machine. The entire cloud platform is to provide bandwidth for all users. Once one of the customers is attacked, at least in the current situation, the normal access of other customers cannot be 100% guaranteed, the bandwidth will be completely occupied, and the CPU will be completely occupied.
This seriously threatens the normal operation of the entire cloud platform. Another important reason is that bandwidth and defense are actually allocated by the entire cloud platform.
Let's talk about standalone servers (physical machines). As we all know, a standalone server is a standalone machine installed in a computer room. It has independent defense, memory, hard disk, bandwidth, IP and other configurations, and an independent operating system. The customer rents the server and uses it independently. Independent servers are usually configured with high bandwidth and strong overall performance, suitable for large-scale applications.
Cloud servers follow the cost-effective route. However, independent servers (physical machines) with high security must adopt a stable defense route, which leads to conflicts between the two cannot be coordinated.