How do people and animals learn responses through classical conditioning?

People and animals learn response through classical conditioning by association. And by association, I mean, linking the corrent situation/concept with another that already experienced in the past. This generally happens through points of similarity. It also has to be repeated to register in the human or animal mind. An example, when a mom tend her hand to her child to cross the street, the child will take the hand and prepare him/herself to cross the street, there is no need for a verbal clarification. By only linking the hand gestures and the place, the child knows that he/she is going to cross the street therefore he/she must crab his/her mother’s hand.