Lead - Contact - Potential

Lead - Contact - Potential

I'm just getting set up and trying to understand the difference between Lead, Contact and Potential.
We are a custom closet company, B2C. Our process involves
 -Customer contacts us
 -we take down customer info and set up an apt to design the closets
 -communicate back and forth about design and details
 -sell the job
 -install the job

I am thinking I can utilize the 3 categories as;
 Lead=Before job is designed
 Potential=after job is designed
 Contact=after job is sold

Does this seem like it should work?