A VPS is a virtual private server.  It is like a dedicated but it is on a server that is using virtualisation software to create the server.  There are also servers that uses the virtualisation in the Linux kernel to handle it; you actually get access to the physical core and not a virtual core so they are better but more expensive.  You get root access to the VPS so you are feel to install such things as the jitsi server.  The self install will install jitsi and the jitsi videobridge and any dependents that are missing.