When you start a business, your business will cost you money. There will be many expenses: you have to pay for the development of the product, your advertising, etc. etc. At the same time, there will be no, or very little income. Because you have nothing to sell yet, or because your potential customers haven't found you yet.
If all goes well, over time your expenses will go down and/or your income will increase. At some point in time, your expenses will match your income. This is the 'break-even point': no profit, no loss.