"Advise and consent" means that important people in the government have to give their opinions, or advice, about something before it can happen, like when choosing a new judge or ambassador. It's like when you ask your mom if you can have ice cream before dinner, and she asks your dad for his opinion too. They both have to agree before you can have the ice cream. Just like that, the government has to work together and agree on things so that everyone is happy and things run smoothly.