An economic moat is a competitive advantage of a company in comparison to others.The moat can be anything like Brand value, patent, etc.
4. Value
Most Famous Quote of Warren buffet -
Price is what you pay, value is what you get.
The value of investing is buying shares at less than their intrinsic value.
5. Margin of Safety
Warren Buffet always looks margin of safety before investing in any company. He only invests, if the company is currently at a discount.