Services
After you receive a fresh server, your machine is more or less empty. You can add so called services to the VM which will install and configure all necessary components.
Note
Keep resource usage in mind. For example, you wont be able to add a 2GB memcached instance on a server with 1GB RAM
Warning
While you can mix most of those services, some of them will work rather nicely together, but others wont due to different requirements. In many cases, it is more feasible to spread services over multiple servers.