Master Inspection Characteristics Vs Control Plan

Dear Team,

I could not able to understand the difference between Master Inspection Characteristic (MIC) created in t.code QS21 & Control Plan (CP) being created in QPCP transaction. Could anyone guide me on the below.

1. What is difference between MIC & CP?

2. On what kind of business scenarios MIC & CP will be created?

3. How to assign CP in routing / reference operation set?

Thanks