Strange htaccess rules

Never this these before. Someone care to clue me in please:

# BEGIN WordPress

<IfModule mod_rewrite.c>

RewriteEngine On

RewriteBase /

RewriteCond %{REQUEST_FILENAME} ^wp-content.*

RewriteCond %{REQUEST_FILENAME} ^wp-admin.*

RewriteCond %{REQUEST_FILENAME} ^wp-include.*

RewriteCond %{REQUEST_FILENAME} !-f

RewriteCond %{REQUEST_FILENAME} !-d

RewriteRule . /index.php [L]

</IfModule>

# END WordPress

Reference: http://forums.digitalpoint.com/showthread.php?t=1656666

Looks like some form of security but nothing I’m used to.