Apple Inc. (AAPL) has a book value the likes of which no corporation has ever seen. After trading places with Exxon Mobil Corp. (XOM) several times atop the list over the last few quarters, Apple’s share price has since risen while Exxon Mobil’s has fallen, giving the former about a $200 billion advantage. The gap between Apple and the next largest company is greater than the market capitalizations of all but about 15 corporations or so around the world. (For more, see: The Apples and Exxons of Years Past.)

Meanwhile in South Korea, Samsung isn’t a company so much as it is a galaxy filament dwarfing everything in its path. By some estimates Samsung is responsible for 1/6 of that nation’s gross domestic product. The businesses that Samsung isn’t in are few and mostly irrelevant. The conglomerate’s main subsidiaries include colossal life insurance, construction, and shipbuilding businesses, but far and away its biggest moneymaker across the globe is also its best-known: Samsung Electronics. (For more, see: How to Invest in Samsung.)

Phoning It In

Samsung has a market capitalization of about $154 billion, barely a quarter the size of Apple’s. But if you believe that a company should be measured by how much it sells, rather than collective market opinion, it’s Apple that’s the second-largest electronics multinational in the world, behind only Samsung. The former sold $171 billion worth of phones, tablets, and related devices last year; the latter, $213 billion. (For related reading, see: Steve Jobs and the Apple Story.)

Samsung Electronics, and that’s the entity we’ll be referring to as “Samsung” throughout the remainder of this article, is not merely an Asian analog to Apple. Samsung has three divisions – consumer electronics, device “solutions,” and IT/mobile. If those sound like synonyms, they aren’t. Consumer electronics in this context means big boxes – TVs, kitchen appliances, air conditioners and washing machines. Device solutions refers to semiconductors, integrated circuits, LED panels, hard drives and other components, rather than standalone devices. That leaves IT and mobile, which indeed includes the cell phones and tablets that are traditionally associated with Samsung, at least in North America.

Huge Margin on iPhones

Apple makes money on iPhones and MacBooks, more than anything else. The phones outsell the laptops 5-to-1, but the massive margins on the latter make the race more or less a wash. Samsung’s profit center is more evident. Its mobile phones that are responsible for 60% of the company’s earnings. Samsung might beat Apple on market share for mobile phones, but Apple happily sells fewer phones than Samsung given that it means netting close to $400 profit per unit. That being said, other departments have begun to account for a greater portion of Samsung’s profits in recent quarters. It’s the oft-overlooked semiconductor unit that’s been leading the charge in 2014, increasing its profits by 82% over last year; even while operating profit declined for Samsung as a whole over the past year. Data storage is a valuable and increasingly in-demand commodity, and there are only so many places that supply it. (For related reading, see: The Key to Apple's Scale? Half a Billion iPhones.)

On Store Shelves and in the Courts

Apple and Samsung have a turbulent relationship, one that’s only gotten more agitated with time. Nor is that dislike without justification. In 2011 Apple sued Samsung, arguing that the Galaxy S and Galaxy Tab ripped off the iPhone and iPad respectively. Samsung countersued a week later, claiming that Apple stole its wireless networking technology. The companies ended up suing each other half a dozen times that year, in courts on four continents. In 2014 Apple won a $929 million judgment in its initial North American suit, which Samsung then appealed. Later, Apple won a second lawsuit. That summer the companies reached some sort of a détente, dropping all suits outside the United States but continuing their courtroom battles in the country where litigation is the national pastime. (For more, see: The Fallout of the Apple vs Samsung Battle.)

Still, a Symbiotic Relationship

What makes this case, or series of cases, unusual is that plaintiff and defendant have a lucrative and symbiotic relationship. Through its many subsidiaries, Samsung sells parts for the very Apple mobile devices it’s allegedly copying without authorization to the tune of $8 billion a year. Apple is Samsung’s biggest customer for several reasons, some of them strategic. Size means getting first crack at supply, which means that in times of high demand Apple can increase its orders with Samsung and let smaller competitors worry about where to find parts.

Samsung fabricated most of the A4 and A5 processors found in Apple’s mobile devices. However, those processors’ heyday was several generations ago. Apple is now up to the A8X chip in its latest version of the iPad Air, a processor made by…a company other than Samsung. (For related reading, see: Inside Intel: A Look at the Mega Chipmaker.)

Whether in business or in life, no matter how lucrative and mutually beneficial a hostile partnership is, at some point the principals start seeking gratification elsewhere. That’s why after years of rumors, in the summer of 2014 Apple finally made it official that it was doing business with Taiwan Semiconductor (TSM). Taiwan Semiconductor’s stock made a predictable jump after the announcement, and continues to trade at a robust clip (while enjoying 30% profit margins). At the same time Samsung acknowledges that the external markets for its chip business aren’t what they used to be. Read between the lines uttered by the company’s CEO, and you’ll realize that that’s code for “Our relationship with Apple is closer to the end than to the beginning.” (For more, see: Forget Apple: Invest Your Next Tech Dollar in Asia.)

The Bottom Line

Apple is so big that it can live comfortably without Samsung. Similarly, Samsung doesn’t need to be an Apple vendor to flourish. As competitors in the marketplace, they’ve put life-changing electronics in the hands of hundreds of millions. As competitors in the halls of justice, they’ve spent enormous sums of money to assert their dominance. Regardless of the legal outcome(s), it’s a safe bet that both companies will continue to innovate for decades more. (For more, see: Forget Apple vs. Samsung: Qualcomm Wins Either Way.)