A virtualised server combines physical hardware that is broken down into separate systems with the help of software. These servers can then be used and shared by several users. In fact, the resources available in the actual server (CPU, RAM, and memory) are divided.
A dedicated server is yours alone to use. Comparable to a laptop or a home PC, the installed resources / components / hardware (CPU cores, RAM, memory, network access, etc.) are used exclusively by one person.