Cannot GET / / : 서버의 root. 첫 페이지. GET : HTTP method Summary: 1. Once you create a server, you need to make server respond to user requests. 2. Users request using HTTP protocol. This request is called GET request. 3. When they type in the URL in the address bar and the page loads, they are actually sending a GET request to a server, getting a response and displaying a response on the browser. I ..