tobias_.MerZ

With Browser Caching you can tell Browsers when your files usually change, e.g. every month, every week, etc. This will fasten up your website because Browser will only make requests to your Server after the declared time. PageSpeed is a Google Ranking Factor so it is important to have a fast website. 
There a several ways to enable Browser Caching. This Plugin uses Expires. The following code will be added to your .htaccess file:
ExpiresActive On
ExpiresByType text/css “access plus 1 month”
ExpiresByType text/javascript “access plus 1 month”
ExpiresByType text/html “access plus 1 month”
ExpiresByType application/javascript “access plus 1 month”
ExpiresByType application/x-javascript “access plus 1 month”
ExpiresByType application/xhtml-xml “access plus 1 month”
ExpiresByType image/gif “access plus 1 month”
ExpiresByType image/jpeg “access plus 1 month”
ExpiresByType image/png “access plus 1 month”
ExpiresByType image/x-icon “access plus 1 month”
The second line means that css files will be requested after 1 month. The third line means that javascript files will be requested after 1 month and so on. 
Of course you can change the periods. You will find instructions for that in the FAQ section.
In case you do not have reading rights to the .htaccess file you will get a 403 Permission Denied Error Page. So before activating this Plugin make sure you have reading rights to the .htaccess file (normally you have those rights).

Browser Caching with .htaccess

Speed up your website with Browser Caching. This Plugin enables Browser Caching in your Apache Web Server, which will make your website faster.

W3 Total Cache vs Browser Caching with .htaccess