Both Jobs and Leads are considered Projects where you can work with your client. There is really no set definition! It is what you define it as.
But you can go off of this framework:
A LEAD is a potential client. This lead has not been a confirmed booking yet. Either hasn't paid an invoice or signed a contract or set a date, etc...
A JOB is a for sure booking. Whatever definition of that is for you...but this potential client is no longer potential...they are guaranteed!
At any point you can move a lead over to a job and a job back to a lead if you'd like. We make that easy for you to do!