What is crochet hair?

gahh so since school is approaching up, my mom wants me to do my hair. my suggestion was to do micro braids, but she insisted i should i get crochet?? 0.0 wat the heck is that lol. does it look good? can u get extensions for it? lol i dont know because when i got extensions they REALLLY damaged my hair. so will this will? please help and thx :)