Here is an excerpt from an article written by Joan Magretta for the Harvard Business Review blog. To read the complete article, check out the wealth of free resources, and sign up for a subscription to HBR email alerts, please click here.

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Michael Porter, the world’s leading authority on competition and strategy, is sometimes the victim of his own success. We use his terminology every day — competitive advantage, the value chain, differentiation, value creation. We think, therefore, that we “know” his work. But in fact, most managers don’t. They talk the talk, but they have turned his powerful ideas into business buzzwords. Competitive advantage, for example, is often used to mean “anything we think we’re good at.” Any plan or program is called a strategy. Managers confuse differentiation with being different.

That’s more than just too bad. I’ve had the rare opportunity to see Porter with fresh eyes — rare because when I approached him some time ago with the idea of writing a concise, practice-oriented guide to his work on competition and strategy, he agreed to give me complete access to his most current work as well as the original classics. My premise in writing Understanding Michael Porter was very simply that clear strategic thinking is essential for any manager in any setting, and Porter’s work lays out the basic principles and frameworks you need to master.

My goal was to present the essential Porter in a form that could be more easily digested and put to work than the original. Having worked directly with Porter for almost two decades, and having applied his ideas during my years as a strategy consultant, I was arrogant enough to believe I wasn’t going to learn anything new. Wrong. When you put that body of work all together, when you integrate the new with the old, you tap into a rich vein of practical and often surprising insights. Not least among them is that most companies think they have a strategy when they don’t.

So as I worked on this book, I kept a list of those insights. Here it is.

[Actually, here are the first four of 1o. To read the complete article, please click here.]

1. Competitive advantage is not about beating rivals; it’s about creating unique value for customers. If you have a competitive advantage, it will show up on your P&L.

2. No strategy is meaningful unless it makes clear what the organization will not do. Making trade-offs is the linchpin that makes competitive advantage possible and sustainable.

3. There is no honor in size or growth if those are profit-less. Competition is about profits, not market share.

4. Don’t overestimate or underestimate the importance of good execution. It’s unlikely to be a source of a sustainable advantage, but without it even the most brilliant strategy will fail to produce superior performance.

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Do these seem self-evident when you stop to think about them? Or do you find, as I do, that they run counter to the way most managers think and behave? That’s why I’d argue that Porter’s work, while never trendy, has never been as timely for so many people working in both the private and public sectors as it is today. Amidst the enormous economic upheaval in many industries and countries around the world, strategy itself has come under fire. Porter’s fundamentals keep you grounded. They explain not only how companies sustain competitive advantages for decades, but also why strategy is even more important — not less so — in turbulent and uncertain times.

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Joan Magretta is a senior associate at the Institute for Strategy and Competitiveness at Harvard Business School. She is the author of Understanding Michael Porter: The Essential Guide to Competition and Strategy. To check out additional blog posts by Joan Magretta, please click here.