I think different cultures use different terms for billable. The company I work with discusses the project with the customer and sells them a set of hours before the deadline (note that does not mean we sell 40 hours and you get the product in 1 workweek). Now like @mutt mentioned, you hire humans and not every minute of the billed hour might be used purely on coding. My company sells a x amount of hours but most of the time we spend more time on the project(don't quote me on this as many businesses work differently and i am not involved in the billing process here)

I think different cultures use different terms for billable.

The company I work with discusses the project with the customer and sells them a set of hours before the deadline (note that does not mean we sell 40 hours and you get the product in one workweek). 

Now like @mutt mentioned, you hire humans and not every minute of the billed hour might be used purely on coding. My company sells an x amount of hours, but most of the time we spend more time on the project  (don't quote me on this as many businesses work differently, and I am not involved in the billing process here).