You use "will" to form future tenses - the action of the verb will happen in the future.
You use "would" to form the conditional - the action of the verb could happen.
"The job will be done by Monday." - The job is certainly going to be finished before Monday or on Monday.
"The job would be done by Monday." - The job is not going to be finished before or on Monday, because of a specific reason. You could say, for example - "The job would be done by Monday, but it won't because it will rain all the time."
"I will meet you this afternoon." - There is no doubt that I will meet you this afternoon.
"I would meet you this afternoon, (but I have other things to do)." - I will not meet you, because I have other things to do. But, if I didn't have these things to do, I WOULD meet you.
Hope it helps at least a bit :)