Under your pipeline you will see a data picker and a list of boxes.
New leads are all the leads that come into your account, this is unassigned new leads.
These are only the leads that have made it into any stage of your sales pipeline, it doens't matter what stage, but as soon as they go from working into a pipeline stage, they are considered qualified.
Leads that have gone all the way thought your pipeline and are marked as "won" will be considered converted.
This is the percentage of leads that are qualified, meaning they have touched a pipeline stage, and become won.
When you add a financial amount to a deal, the amount that is marked in the Won deal will show as your revenue for that pipeline.