What a Haiku Is

If you type ''haiku'' in the search, You will get a bunch of 3- line poems, which you may not understand. Well, here is what a haiku is:
Haiku is the name of a type of poem from Japan. All haikus have 3 lines. The first line has 5 syllables and usually introduces the subject. The second line has 7 syllables and often describes what the subject is doing. The third line has 5 syllables and acts like a kind of punch line.