“Work” is a general term that refers to all activities that one does while “Job” is more specific.

JOB: an activity that an individual performs in exchange for a specific fee or payment. Also called a profession or an occupation.

We use “job” to talk about the specific position someone has at a company.

• My job is too stressful, so I’m looking for another one.

The word Job is a Countable Noun:

• I worked two jobs so that I could pay off my student loans faster.
• Mark has had seven jobsin the past five years.

WORK: is defined as “a physical or mental activity that is performed in order to accomplish or produce something.

“Work” refers to general efforts and activities done to accomplish a goal.

We use “work” with the following expressions: go to work, get to work, arrive at work, get off work, leave work, finish work, and take off work. We cannot use “job” with these expressions.

Example:

• I have a lot of work to do tomorrow 
• You can say you work at/for (a company): “I work at General Motors.”
• You can say you’re working on (a project/task): “I’m working on a market analysis”
• You can say you work with (people/objects): “I work with special needs children”

The word Work is an Uncountable Noun, so it is not used in the plural:

I have some work to do (some tasks/activities)

What’s your job? Where do you work?

Can you give us an example sentence using Job/Work in the comments?