whats with thoughs sqiggly lines!?

hi! ok, you no when you make a blog, there is those sqiggly lines that are hard to read?! like this:
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why do they have that!!! is it to see if you're drunk! i never get those!!! sometimes they can be really hard, and you get stuck on them for like 20 minutes!!! but some can be really easy!!! i usually get stuck on them, but as you can see, i worked them out!!! don't worry though, i'm to young to get drunk..... (lol) does anyone no what they're ACTULLY for?
anyway, yesterday was monday, and i had to go to the town hall for choir practise, it was 2 and a half hours long, and we wern't allowed to eat or drink!!! lucky i brang some snacks in my pocket..... (i'm guilty!) i'm just about to go to school, i'm BORED!!! this is officaly an S.O.S!
luv cate xx