Either an external client or another department within your organization.
Using Billing Methods, you can set a fixed fee on a project or a billing rate per person, project, tasks, ...
It is a standard cost that you have to evaluate based on past data.
The cost is set per employee using Standard Cost on the employee page.
report or chart:
budget sets an amount or a number of hours budgeted for a project and/or subprojects.
Each time an employee records an hour, the budget is consumed by the respective amount or time.
The budget status indicates the initial budget, and how much is left in the project/subproject.
In this case , the profit is $20 ( 100 - 80 ) per hour or ( 100 - 80 ) / 100 * 100 = 20%
And this consume the budget by 100€.
In budget status, you can see the remaining budget is then 900€ or 90%.