Post/Redirect/Get (PRG) is a common design pattern for web applications, to help avoid duplicate form submissions and allow web applications to behave more intuitively with browser bookmarks and the reload button.
After a web user submits a form to a server, the server typically generates an HTML page as a response. To the user, this looks like an ordinary web page, but because it was generated by an  POST request, it cannot be bookmarked, and attempting to reload/refresh the page in the browser could cause the form information to be resubmitted, possibly with unexpected results (such as a duplicate purchase).
To avoid this problem, many web applications use the PRG pattern — instead of returning an HTML page directly, the POST operation returns a redirection command (using the HTTP 303 response code (sometimes 302) together with the HTTP "Location" response header), instructing the browser to load a different page using an HTTP GET request. The result page can then safely be bookmarked or reloaded without unexpected side effects.
READY TO CUT LOOSE Mario Williams Says Bills' Aggressive New Schemes Will Allow the Defensive Front to 'Get after It' against Patriots ; Mario Williams Says Bills' Aggressive New Schemes Will Allow the Defensive Front to 'Get after It' against Patriots
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