Apple and Samsung's battle for mobile supremacy heads to a court in California today in one of the biggest ever technology patent trials.
The two firms have accused each other of intellectual property infringement with billions of dollars and potential sales bans resting on the outcome.
Why the stakes are high for Apple and Samsung:
- Samsung are facing a potential US sales bans of its Galaxy smartphones and tablet computers.
- Apple are facing a pivotal test of its worldwide patent.
- Both sides are seeking financial damages from the other. Apple are seeking at least $2.53 billion - this amount could be increased if Samsung are found guilty.
Samsung has rapidly overtaken Apple - the creator of the iPhone and iPad - and Nokia, to become the world's largest smartphone maker. Together, the two tech firms account for more than half of smartphone sales globally.
The iPhone maker will try to use Samsung documents to show its rival knowingly violated Apple's intellectual property rights.
Samsung will argue that Apple is trying to stifle competition to maintain "exorbitant" profit.
In a statement last week, Samsung said Apple had been "free-riding" on its technology "while using excessive legal claims against our products in their attempt to limit consumer choice and discourage innovation."
An Apple spokesman reiterated the company's previous statement that it wasn't a coincidence Samsung's latest products looked a lot like the iPhone and iPad, and that Samsung copied its products.
Samsung are estimated to have increased sales to around 50 million smartphones. That helped the South Korean giant to report a record quarterly profit of $5.9 billion on Friday.