IO intensive vs CPU intensive

[lukenhung]

Hi everyone,
I have planed to take OCPJP exam at the begin of next month, now I am very happy with Enthuware Studio Test and I believe I can pass the exam with Enthuware Studio .
During my preparation, I have a little confused about IO/CPU intensive,I have searched them on Google but I still have not found my answer . Can someone please tell me what they are ? and how to detect a task is IO or CPU intensive?

Thank in advance.

[admin]

If your process does a lot of reading/writing from/to a file or from/to network, it is an I/O intensive process. If it does a lot of computation, then it is a CPU intensive process.
For example, reading all the names from a phone book database is an i/o intensive process but sorting the names is a CPU intensive process.