Remember that time when we were reporting all about the potential looming 'trade war' between China and the US? Yeah, that's back.
What it means: For a while, the US and China were throwing 'oh yeah-well-listen-to-this' style threats back and forth about placing limitations and barriers on trade with each other. Trump threatened to put taxes on Chinese goods sold in America so that less people would buy them. China came back with the same threat, the other way round. Eventually they both kind of left it.
He says it's about protecting 'intellectual property', which is just a way of saying America's 'know-how' of how to produce good tech. Intellectual property is an extremely valuable asset - if China cracked the US' code on how it produces electronic goods, they could go back to China and make all the same ones for less