Defining Operating Conditions in PD using SoC Encounter

I am using SoC encounter for project. I want to introduce operating conditions into the flow.

1. How these operating conditions are defined?
2. Is it dependent on Synthesis & RTL?
3. On what basis these operating conditions are decided?
4. What is the difference between prePD and postPD netlist?

Answers:
1. Using setOptCond command.
2. No.
3. Normally best case and worst case operating conditions is used for SoC           encounter do timing optimization for setup and hold.
4. PostPD netlist has complete clock tree structure and so more accurate               timing analysis with wire capacitance.