I have moved host providers, and my new provider uses CloudLinux.
CloudLinux uses a container technology called Lightweight Virtual Environment, or LVE. This container technology allows many users to co-locate on the same server. Each tenant is limited to specific resources and cannot exceed them and thus, negatively influence the other tenants.
Physical Memory Usage (RAM) is a combination of physical memory and disk cache. When physical memory usage is close to max CloudLinux will dump its disk cache to free up space. If physical memory usage is still maxing, users will experience PHP error 500 and 503s.
Virtual Memory Usage corresponds to the amount of memory, processes can allocate within LVE.
Entry Processes: the number of processes that enter your account. A visitor usually asks for numerous resources, each resource is an entry process.
Number of Processes: all processes generated by the account, including PHP, SSH or cron jobs.