These are four different words because they are four different things.
Hobby – Something that you do purely for pleasure. You don’t need a hobby. You do it because you want to.
Job – This is the only one of the four you do need. You have to have a job. Something to pay the bills. It doesn’t have to be awesome, fulfill you, or be joyful. It just has to pay.
Career – A career is something that you are passionate about. You should love your career, or not have one. You do not need to have a career. If you are in a career that you hate, quit your career and go get a job that pays the bills and lets you focus on other things.
Vocation – The holy and most sacred vocation. A vocation is a calling. A vocation is the voice of the universe in your ear saying, “I want you to use your talents and gifts to do this.”
Here’s the thing about a vocation: nobody can take it from you. Nobody can give it to you, and nobody can take it from you.
Somebody can take your job away from you.
Somebody can take your career away from you.
Nobody can take your vocation. Except for maybe you.
Having a job or career is not a good enough excuse to pass on a vocation that is calling.
You may need to make a change.
But if you feel a calling, the change will be worthwhile.
This post is my summary of a video from Elizabeth Gilbert, which I highly recommend watching: https://www.youtube.com/watch?v=0g7ARarFNnw