Description of few parameters of top command:
wa = Waiting for I/O
us = User space
sy = system/kernel
ni = Nice Process
id = Idle
hi = Hardware Interrupts
si = Software Interrupts
EDIT:
1. us -> User CPU time: The time the CPU has spent running users’ processes that are not niced.
2. sy -> System CPU time: The time the CPU has spent running the kernel and its processes.
3. ni -> Nice CPU time: The time the CPU has spent running users’ proccess that have been niced.
4. wa -> iowait: Amount of time the CPU has been waiting for I/O to complete.
5. hi -> Hardware IRQ: The amount of time the CPU has been servicing hardware interrupts.
6. si -> Software Interrupts.: The amount of time the CPU has been servicing software interrupts.