Form submission typically redirects to a PHP file because it is the server-side language responsible for processing and handling data submitted from a form. The PHP file receives the form data, performs any necessary actions or calculations, and then can redirect the user to another page or display a response message.
When a form is submitted, the data is sent to the server using the POST or GET method, and the server uses the PHP file specified in the form's "action" attribute to handle the submitted data. This PHP file can perform tasks such as storing data in a database, sending emails, validating input, or generating dynamic content.
After the PHP file has processed the form data, it can redirect the user to a different page by using a redirection function or by sending an HTTP header with the desired location. This redirect helps prevent resubmission of form data if the user refreshes the page.
Overall, the PHP file acts as an intermediary between the form and the server, allowing the server to process and respond to the form data appropriately.