Life hacks are little things that make life easier - and the best ones make you go "duh, why did I never think of that" and then use that little thing and wonder how you ever managed without it.
And from time to time, lists with life hacks pop up on the internet - such as this one. Some of those I already knew (and use), some of them are quite American, and quite a few just do not apply to me because I do not have the need (I can separate eggs like a boss, without a squeezy bottle.) But they are fun to look at nevertheless, I think.