http://www.bbc.co.uk/worldservice/learningenglish/language/askaboutenglish/2009/03/090331_aae_work_page.shtml

http://www.usingenglish.com/handouts/57.html

Firstly, on a grammatical level, work is both a verb and a noun, whereas job is only a noun.

 Generally, we work in order to earn money, and this is often how we use the verb; to describe what we do to earn money. For example:

 I work for the BBC.

David works in a caf�.

In these examples, we do not know exactly what the person�s duties or responsibilities are. David works in a caf�, but we do not know if he cleans the tables or cooks the food.

 So, in this sense, work has a very general meaning, whereas job is much more specific, and its most common meaning is the name for the work that you do to earn money. For example,

 David has now got a new job. He is a cook in a small restaurant.

 In this example, we now know exactly what David does because we know what his job is. To summarise, we can say that the word job refers to a particular employment role or position, such as cook, teacher or banker, whereas work refers in a more general way to activities that you do.

Hope this helps.