Answers for "what is the htaccess file"

.htaccess

##Add a Trailing slash
# FROM:  http://was-mit-internet.de/unterseite/filename.html
# TO: http://was-mit-internet.de/unterseite
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !(.*)/$
RewriteRule ^(.*)$ https://www.domainname.tld/$1/ [L,R=301]

.htaccess

# No extern use from your images
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?domainname.de [NC]
RewriteRule \.(jpg|jpeg|png|gif)$ https://domainname.de/hotlink.jpg [NC,R,L]

.htaccess

# Browser Caching
ExpiresActive On
ExpiresByType image/jpg "access 1 month"
ExpiresByType image/jpeg "access 1 month"
ExpiresByType image/gif "access 1 month"
ExpiresByType image/png "access 1 month"
ExpiresByType image/x-icon "access 1 month"
ExpiresByType text/css "access 1 month"
ExpiresByType application/pdf "access 1 month"
ExpiresByType text/x-javascript "access 1 month"
ExpiresByType application/x-shockwave-flash "access 1 month"
ExpiresDefault "access 3 days"