Pricing procedure Steps and Details in SAP MM (from SCN)

http://scn.sap.com/community/erp/logistics-mm/blog/2013/11/27/pricing-procedure-details-and-steps-in-sap-mm 

Pricing procedure for Purchase order :
Path :  IMG -- > MM -- > Purchasing -->Conditions --> Define Price Determination Process

Explain the pricing procedure used in Purchase Order