Apple and Qualcomm have headed into court for the first day of their long-awaited legal battle.
The two companies have been at legal war for the last few years, because Qualcomm believes it's owed more money from the tech giant for producing the chips for its iPhones and iPads.
The firms have been arguing since 2017 when Apple claimed Qualcomm was charging too much for its chips. It said that just because Qualcomm leads the phone processor industry, that doesn't give it the right to charge above and beyond other manufacturers.
However, Qualcomm's defence is that the cost doesn't just cover the physical materials of the chips, but also the patents the company owns and uses in its processors. These have allowed the company to become a leader in its field and so it's charging Apple and other manufacturers by way of a licence fee.
Apple is using the five-week trial as a route to recoup some of the money it's paid Qualcomm over the last few years - estimated to be in the billions of dollars. However, Qualcomm is counter-suing to claim back the costs it's incurred due to contract breaches with the company.
If Apple does succeed in claiming money back from the chip-maker, it could cost a lot more than Qualcomm bargained for, potentially sparking legal claims from other smartphone and tablet manufacturers. Qualcomm has already paid significant fines in China, South Korea and Taiwan, following claims it has been over-charging for its tech.
But Apple hasn't found itself in a favourable position either. The iPhone 7 and iPhone 8 were withdrawn from sale in China and Germany following an injunction granted to Qualcomm in those territories, hitting the company's revenues hard.
