Berkshire Hathaway (BRK.A -0.76%) (BRK.B -0.69%), the conglomerate that Warren Buffett has run for nearly 60 years, owned a lot of different stocks over the years. Some didn't work out, but some of them turned out to be huge wins. 

One of the best investments in recent years was the decision to buy shares of Apple (AAPL -0.35%). Buffett first bought a stake in the iPhone maker in the first quarter of 2016. Since the start of that year, a $10,000 investment would have turned into about $68,000 (as of Aug. 9), translating to a monster return of 579% that trounces the overall market. 

It's important for investors to understand where this top tech business has been before considering buying the stock right now. 

Apple's attractive qualities 

It's not difficult to figure out why Buffett was drawn to Apple more than seven years ago. For starters, the company is known for selling some of the most in-demand products in the world. Buffett likes to own businesses that delight their customers, and Apple does this better than anyone else. The iPhone, for example, continues to introduce new upgrades that consumers absolutely love. 

Not too long before Buffett invested in the company, Apple released the first model of the Watch in April 2015. And after Berkshire was already a shareholder, the company launched the AirPods in September 2016. Both products have been fantastic success stories. 

Buffett realized that a more accurate assessment of Apple would be possible by viewing it as a consumer brand instead of just a tech business. Without a doubt, Apple's economic moat, a term Buffett is famous for coming up with, stems from its incredible brand recognition. According to Interbrand, Apple has the most valuable brand in the world, worth an estimated $482 billion. 

Apple's financial situation was outstanding. In fiscal 2015 (ended Sept. 26 of that year), the company posted revenue and diluted earnings-per-share growth of 28% and 43%, respectively, with cash, cash equivalents, and marketable securities of $206 billion. The thinking was probably that Apple's earnings power would be significantly higher five or 10 years from then, prompting the Oracle of Omaha to be extremely intrigued by Apple's trajectory. 

Buffett also takes a long hard look at the leadership team running a particular company. When Steve Jobs passed away in 2011, investors thought that Tim Cook wouldn't be able to be as successful in guiding Apple to new heights. But we've learned that this assumption was wrong. Even Buffett agrees. "Tim Cook has managed that company in an extraordinary way," he said about Apple's current CEO. 

At the start of 2016, Apple's market capitalization was just under $600 billion, so it was the world's most valuable company then, too. But the stock's trailing price-to-earnings (P/E) ratio on Jan. 1, 2016, was 11. Certainly, Buffett viewed this valuation as being very attractive. 

What about now? 

Any investor would benefit by not only studying the great investors, but by also learning about successful investments. Buffett and Apple, respectively, fit into these categories without question.

At a market capitalization of $2.8 trillion right now, and with the stock trading at a trailing P/E ratio of 30, Apple is obviously selling at a much higher premium than when Buffett got involved. But Berkshire is likely still a shareholder because of the huge dividends that the company receives thanks to its nearly 6% stake in the tech giant. 

For the individual investor thinking about buying Apple today, it's best to accept the fact that the business likely won't register the same monster growth in the future that it has posted in past years. Nonetheless, it wouldn't be surprising if Apple introduced another game-changing product or service that moves the needle financially.