启用浏览器缓存时如何处理文件更改？

Question

I found the following cache htaccess rules but I have 2 questions

1. Is the one for PHP included in this? Is is under the "html" since it runs on server and results are shown to client?
2. Second question is let's say I made some css changes to theme.css. I suppose that a visitor will not get the new version, so should I add it something like theme.css?7362340 with a different sequence every time I made changes ?

Here is the htaccess

<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType image/jpg "access 1 year"
ExpiresByType image/jpeg "access 1 year"
ExpiresByType image/gif "access 1 year"
ExpiresByType image/png "access 1 year"
ExpiresByType text/css "access 1 month"
ExpiresByType text/html "access 1 month"
ExpiresByType application/pdf "access 1 month"
ExpiresByType text/x-javascript "access 1 month"
ExpiresByType application/x-shockwave-flash "access 1 month"
ExpiresByType image/x-icon "access 1 year"
ExpiresDefault "access 1 month"
</IfModule>