Hi,
TOP provides an ongoing look at processor activity in real time. It displays a listing of the most CPU-intensive tasks on the system, and can provide an interactive interface for manipulating processes. It can sort the tasks by CPU usage, memory usage and runtime. can be better configured than the standard top from the procps suite. Most features can either be selected by an interactive command or by specifying the feature in the personal or system-wide configuration file.
ESXTOP is VMware's version of this popular "top" command that run on an ESX or ESXi server. Both top and esxtop run only at the command line of a server. You would access these commands by either going directly to a server console or by connecting to a server remotely via SSH (or telnet, if enabled).