I am trying to find short explanation of different transitor and cap models present in Cadence gpdk045 design kit. From where i can find the information about the differences between transistor models like, nmos1v, nmos1v_hvt, nmos2v, nmos1v_Ivt, nmos1v_nat, etc.
Process Design Kit, the description of the process, its libraries, sim. models, design & verification rules, tape-out procedure: all the explanations you need to design, simulate, layout, verify & tape-out your design for submission to your foundry.
You receive it from your foundry, or from the organization which represents the foundry and supplies the process software to you (like, e.g., MOSIS).