Question 1: What is the difference between 1 [a] and 1 [b]?
Question 2: What are the processes (system?) that are running that resulted to 1 [b]?
top -S is just giving a name idle: cpu0, idle: cpu1, etc. under the command column.
Question 3: Is it logical to compare the average CPU utilization results obtained in number 1 and 2? How are they differ?
Question 4. Are there other tools that I can use to accurately get the running processes that are eating the actual CPU resources on the machine?