This question is difficult to answerl because it is so vague. If you would consider narrowing down your question to a country, state, industry etc., it may be possible to give you a better answer....
There are SO many careers out there, you just have to have the right schooling. i would say roughly around 143 million careers, so you have a lot to choose from, so choose wisely :)
There are far too many US Army MOS's (Military Operating Specialties) to list. For a comprehensive list of all Army MOS's by branch, see the linked site.
No. A job can be temporary and requiring lesser diligence than a career. For example if your job is a store clerk than your career is marketing,sales etc....