Is there a difference? I think there is. All you have to do is watch the way Jack works and then watch the way Rocket works.
Work may be defined as "activity involving mental or physical effort done in order to achieve a purpose or result".
If you need work done, you should call on Jack. Jack will get the work done for you in the most efficient manner. There will be no fooling around, no extra work will be done, there will be short cuts taken and you had better have a plan for the work to be done. If you do not, you will not be of much use to Jack and he will lay down down on the job. He works hard & if there is Joy at the end of the task, so be it. But it is work to him. And he doesn't do it for the Joy; he does it because it needs to be done.
Jack is all business in everything he does. If he is chasing a Frisbee, it is because it needs to be caught. If he is going for a walk, it is because he wants to get home. There is a stoic quietness to his determination to complete a task that I envy. He puts his head down and forges ahead, no matter what is in his way. I would hire Jack.
If you want to have fun while you work, you will want Rocket as your right-hand dog. You may not complete the task in a timely manner but you will certainly have a smile on your face the entire time. Rocket brings lightness to everything he does. There is a definite smile on his face & a twinkle in his eyes as he puts everything he has into everything he does. He will show you every trick he has in his head to get you to play with him. He will roll over when you want him to be still or shake paws when you want him to roll over. His entire body vibrates when you bring out a ball or he meets a stranger or sees a small dog. His tail is high & his ears are on high alert if you make a move for the door. He is always ready to go no matter if he is tired or sick or has been at a competition all day. He makes everyone around him happy. I would hire Rocket.
Jack finds work in Joy & Rocket finds Joy in work.
What about your dogs?