In his opening statement, Samsung lawyer Charles Verhoeven countered that the South Korean company employs thousands of designers and spends billions of dollars on research and development to create new products.
"Samsung is not some copyist, some Johnny-come-lately doing knockoffs," he said.
Verhoeven asserted that Apple is like many other companies that use similar technology and designs to satisfy consumer demands for phones and other devices that play music and movies and take photographs.
For example, he said, several other companies and inventors have filed patent applications for the rounded, rectangular shape associated with Apple products.
"Everyone is out there with that basic form factor," Verhoeven said.
A verdict in Apple's favor could lead to banishment of Samsung's Galaxy products from the U.S. market, said Mark A. Lemley, a professor and director of the Stanford Program in Law, Science, and Technology.
A verdict in Samsung's favor, especially if it prevails in its demands that Apple pay its asking price for certain transmission technology, could lead to higher-priced Apple products.
Bloomberg News reported that Apple is preparing to introduce the next version of the iPhone on Sept. 12 in what will be a design overhaul, citing two people with knowledge of the company's plans.
Cupertino-based Apple filed its lawsuit against Samsung Electronics Co. last year and is demanding $2.5 billion in damages, an award that would dwarf the largest patent-related verdict to date.
A similar trial began last week, and the two companies have been fighting in other courts in the United Kingdom and Germany.
U.S. District Judge Lucy Koh last month ordered Samsung to pull its Galaxy 10.1 computer tablet from the U.S. market pending the outcome of the patent trial. However, she barred Apple lawyers from telling jurors about the ban.
Apple lawyers argue that there is almost no difference between Samsung products and its own, and that the South Korean company's internal documents show it copied Apple's iconic designs and its interface.
Samsung counters that Apple copied its iPhone from Sony. In addition, Samsung alleges Apple is using some of Samsung's own inventions without payment, such as a computer chip at the heart of the iPhone.