Buying a stock (Level 6) is easy; understanding what you're buying is the hard part. This level gives you the basic framework for reading a real company's financials before investing in it, the same concepts of income, debt and cash flow from earlier levels, applied to an entire business instead of your own finances. The examples use a fictional company, "TecnoNova", to focus on the method, not on any real company.
Revenue (or turnover) is all the money coming in from sales, before subtracting anything. Profit is what's left after paying every cost: production, staff, rent, debt interest, taxes. A company can have huge revenue and still lose money if its costs grow faster than its sales: high revenue isn't the same as a healthy business.
The rest of this level will be available very soon.