Whats the difference between nohup proc & and proc &? I've completely logged out without background procs running with nohup and noticed no difference.
Without nohup, when you exist the console, if the job still keep running , the job will be stopped.
with nohup, when you exist, the job is still running until it finished.
man nohup will give you more detail information.
In addition to what "rdcwayx" stated correctly... The ampersand usage allows the job to run in the background, freeing up the terminal command-line for additional work (you don't have to wait to enter another command). So using both nohup and ampersand at the end, will prevent the job from dying if you log off, but will allow opportunity to use that same terminal window for additional typing in of new commands while the submitted job is still executing.