text: Crochet differs from knitting in that only one loop is active at one time ( the sole exception being Tunisian crochet ) , and that a single crochet hook is used instead of two knitting needles .
simplified: It is similar to knitting , except that usually only one loop is active at one time , and that a crochet hook is used instead of knitting needles . Also , crochet can not be made by machine .