why do people know about WW2 more then WW1?

For Americans part of the reason is that the United States was only involved in WW1 for the final year but involved in WW2 for 4 years also because they were very different wars. WW2 there was a clear bad guy in Hitler and he had to be defeated at all costs, in WW1 it was about old empires battling to maintain their empires. Another reason most people find WW2 more interesting is there are still veterans from that war who are still alive to talk to about their experiences.

The Second World War was more recent.

There are a dwindling number of veterans still alive. A large number of people have a relative alive who had a role in the war (be it a soldier, factory worker etc) or have family members who knew said relative when they were alive. Family members still remember their relative who was killed as a result of the war etc, Thus the war makes up part of the recent family history.

The entertainment industry focuses much more of the Second World War.

The Second World War had a direct impact on the current world situation. Organizations such as the UN and EU were established (directly or in the long run) as a result of the war. The Cold War was a result of the outcome of the war, and lasted until the early 90s. The current situation in Korea can trace its origins back to how the region was divided due to the aftermath of the war etc etc etc

The idea (while on the whole incorrect) of massed tank battles, aircraft swooping around firing rockets blowing crap up etc is 'a bit more interesting' than the perception of a stalemate and no one doing anything other than running at machine guns. A bunch of overgeneralized and incorrect points I know, but it does seem to be how people perceive the wars in my experience.

Because other people find WW2 more interesting. Concentration camps, Anne Frank, Hitler, Nazis

The holocaust museum

It just fascinates people