Cash Flow
  
Cash is like water, always moving. It's flowing and ebbing, sometimes just trickling, its way around. Cash flow just refers to the process of money moving in and out of a business. It involves cash inflows, or money flowing into your business from customers and sales. There's also (unfortunately) cash outflows, like the cash you have to pony up to fix that radiator again. (Also, salaries, utilities, raw materials, etc.)