Jobs accounts

Hi , i am working on Navision 4.0 sp3.

I am going through the JObs.

But i could not understand the use of this accounts
WIP cost , WIP sales,…

What is the use this account ?

it could be better if u throw some example .

could u throw some help on this ?

Not my area, but it relates to the WIP method for the Job, then the periodic activity for calculating the WIP values. The help on teh WIP method is quite extensive and this is your starting point!