Charity shops are similar to thrift shops. The sell old clothes for a cheaper price, but usually when you're giving clothes away, some charities will give you money depending on the weight and what you actually bring. Other charity shops will sell your items and they will use it for the charity that they are. For example, the British heart foundation shop will of course I've the money to the charity and so on. They try and encourage you to give your clothes away to charities so they are not waste, but also they could be used for the homeless or children that are in need.