Samsung Electronics sued Apple Inc over infringing its 10 patents in tablets and mobile technology. The company filed lawsuit against Apple in U.S. while earlier this month Apple sued Samsung and claimed that the Samsung Galaxy line of mobile phones and tablets “slavishly” copies the iPhone and iPad.

Among the phone makers and software firms over which owns patents these two companies are part of wider web of litigation. And these are rivals in smartphone and tablet market.

Samsung is one of the fastest growing companies in the smartphone and tablet market and became a strong contender of Apple. But still it has second rank.

While the Samsung is using Google’s Android OS for its smartphones and tablets, Apple is using its own iOS.

Samsung filed the lawsuit against Apple in California federal court follows litigation initiated against Apple in South Korea, Japan and Germany last week.

According to Samsung, Apple copied many innovations of the company for example, the ability for mobile phones to display the time.

According to lawsuit, “As users travel across time zones, the ability of a mobile device to update to the local time is important for tracking appointments and meetings.”