https://blog.coinidea.com/en/tags/url/Recent content in URL on Coinidea's BlogHugo -- gohugo.ioenThu, 15 Oct 2015 15:24:04 +0000https://blog.coinidea.com/en/p/web-development-what-happens-after-a-user-enters-a-url/Thu, 15 Oct 2015 15:24:04 +0000https://blog.coinidea.com/en/p/web-development-what-happens-after-a-user-enters-a-url/<p>When a user opens a browser and enters a URL:</p> <ol> <li> <p>The client checks whether there is an IP address cached for that URL. If not, it sends a request to the nearest DNS server for domain name resolution, querying up to the root DNS server if necessary. Once the query succeeds, the result is returned to the client.</p> </li> <li> <p>The browser sends the request to the web server at the IP address corresponding to the URL.</p> <p>This server may be a single standalone server, a lightweight load balancer, or a cluster.</p> <p>If it is a load balancer or cluster, the servers internally synchronize based on timestamps to ensure the data is up to date; if not, synchronization is performed.</p> </li> <li> <p>If the request involves application-level calls, the request is forwarded to the application server, which returns the result to the web server.</p> </li> <li> <p>The web server executes programs written in the relevant dynamic languages, communicates with database servers and related files, and finally sends the resulting web page data back to the browser.</p> </li> <li> <p>Based on transport protocols such as HTTP and HTTPS, the web server&rsquo;s data is transmitted back to the browser, which then parses and renders the web page.</p> </li> </ol> <p>Finally, the user sees the web page.</p> <p><img src="http://blog.coinidea.com/wp-content/uploads/2015/10/%e7%94%a8%e6%88%b7.png" loading="lazy" alt="User" ></p>