Everytime you send requests to a website it can track where the requests are coming from, by tracking your IP. If you want send multiple request to a target, which is the case on most websites, the website can track that a bunch of request are coming from the same IP, hence they block you. To counter this, every single request needs to mask the IP they're coming from by sending them through a proxy. In this case, the website doesn't recognize the requests are all coming from the same place. To summarize: Proxies are used to mask the IP of your requests.