While free displays only memory-related information, the top command does a little bit of everything. CPU utilization, process statistics, memory utilization — top does it all. In addition, unlike the free command, top's default behavior is to run continuously; there is no need to use the watch command. Here is a sample display
The display is divided into two sections:
Top provide an self-updating view of your system, including memory usage by process, users on the system, and so forth.