Coca-Cola (KO 0.14%) is Warren Buffett's longest-held stock and one of his favorites. His holding company, Berkshire Hathaway, first bought shares of Coke stock in 1988 and owns 400 million shares.

The big news revealed at the Berkshire Hathaway annual meeting last week was that it had sold 13% of its stake in Apple. While that sounds significant, and is, Apple remains the company's largest position by far, moving down from around 50% to 40% of the total portfolio. However, even though Buffett said Apple was a better business than Coca-Cola and American Express, his other longtime favorite, he has never sold a share of Coke or American Express.

Let's see what he said about Coca-Cola and how that might influence your opinion of it as an investor.

A trio of forever stocks

Buffett often groups Coca-Cola and American Express together. He praises their dominance and how they've carved out exceptional niches in their industries, with strong moats and leadership. Recently, he's added Apple to create a trio of favorite stocks, or as he would say, businesses. He reiterated that he invests in businesses, not stocks, and explained that longtime partner Charlie Munger, who passed away last year, helped him shift his mindset to investigating a business instead of paying attention to the market.

"And that's sort of the story of why we own American Express, which is a wonderful business," he said. "We own Coca-Cola, which is a wonderful business, and we own Apple, which is an even better business."

He gave a further explanation for what it is about Coca-Cola that he finds so compelling:

No company hardly does business around the world like Coca-Cola. I mean, they are the preferred soft drink. You know, something maybe like 170 or 180 out of 200 countries. Those are rough approximations from a few years back, probably, but that degree of acceptance worldwide is, I think it's almost unmatched.

Coca-Cola's global acceptance means that it enjoys high sales and makes it very hard to beat. That's a moat that ensures its survival, and so long as the company keeps it strong, Coca-Cola should continue to perform well, keep up its dividend, and grow.

Where is Coca-Cola holding today?

Coca-Cola remains the largest beverage company in the world, with $46 billion in trailing-12-month revenue. It has successfully raised prices on many of its products because loyal customers are willing to spend for their favorite drink. That's the kind of brand Coca-Cola has developed over time. It has forged relationships with customers that lead to reliable sales, providing it with resilience during rough times. This is the quality that Buffett is describing.

Management recently made some changes to become an even stronger company. It removed half of its brands, about 200 in total. These were mostly local brands that accounted for less than 2% of volume and 1% of revenue. Consider that: Half of its brands were accounting for less 1% of sales. No wonder management decided to do away with them and refocus resources on better-performing brands.

This is what Buffett is talking about when he mentions that Coca-Cola is a global company. The stronger a company's global brand presence, the harder it is to topple from its perch. The more Coca-Cola focuses on its large, global, core brands, the stronger it becomes.

Invest like Buffett

Investors can talk about quarterly earnings and profitability and change their positions accordingly. Or you can think about the business the way Buffett does. "It's such a simple approach that it's almost deceptive," he said. "Most things, if you keep working harder and harder at it ... but investments, you don't really have to do that. You really have to have your mind set properly."

This is a useful paradigm when considering any stock. It can help investors think outside of the near-term box and focus on the long term, where investors can reap the real gains of successful investing.