Hacker News (HN) is a social news website focusing on computer science and entrepreneurship. It is run by the investment fund and startup incubator Y Combinator. In general, content that can be submitted is defined as "anything that gratifies one's intellectual curiosity."

On Hacker News, users receive Karma whenever another user upvotes a submission or comment they made, which incentivizes positive contributions to the community.

There's no stats page but last I checked it was around 5M monthly unique users (depending on how you count them), perhaps 10M page views a day (including a guess at API traffic), and something like 1300 submissions (stories) and 13k comments a day.

On the subject of what to post, the Hacker News guidelines say: "On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity."