I've created first a website using html and css files. now i need to create dynamic pages. done that and they are php pages. should i now rename all html files as php pages or can / should i leave the pages as they are?
make new php or dynamic javascript files and put in the same folder and connect in to html file as <script type ="text/Javascript" src= "your script.js or your script.php"> </script>
You can rename the the html files as .php. They will work same as html files if apache and php is enabled on your server.
you should rename those HTML pages as .php so that Apache sever will recognize the script in it and run it.
you must rename files where php code are written, otherwise all php code will be displayed as text. But if html file doesn't have php code, u can leave it like that.