This is part 3 of 15 part series on building web server with go. Checkout https://www.gophersumit.com/series/web-server/ for more. working with cookies Since http is stateless, various alternatives are used to maintain data between various requests and one such construct is cookie. An HTTP cookie (web cookie, browser cookie) is a small piece of data that a server sends to the user's web browser. The browser may store it and send it back with the next request to the same server.