120
The simple answer is that 5 items can be arranged 5! (5 factorial) different ways. But let's expand upon that brief answer. We have 5 jobs and 5 machines with which to perform those jobs. So let's look at the 1st machine. Any of 5 of the jobs may be assigned to it. Now we have 4 jobs left unassigned. So let's look at the 2nd machine. For that machine, any of the 4 remaining jobs may be assigned to it, leaving 3 unassigned jobs. We can continue in that fashion, assigning at random one the of 3 remaining jobs to the 3rd machine, one of the 2 remaining jobs to the 4th machine, and finally, the only unassigned job to the 5th machine. So there's 5 * 4 * 3 * 2 * 1 = 5! = 120 different ways to assign those 5 jobs to all 5 machines.