You question is not clear enough. A htaccess (hypertext access) file is a directory-level configuration file supported by several web servers, that allows for decentralized management of web server configuration. The original purpose of .htaccess - reflected in its name - was to allow per-directory access control, by for example requiring a password to access the content. Nowadays however, the .htaccess files can override many other configuration settings including content type and character set, CGI handlers, etc. These files are placed inside the web tree, and are able to override a subset of the server's global configuration for that directory, and all sub-directories.
For security: RewriteEngine On Options +FollowSymLinks Options -Indexes DirectoryIndex index.ext ServerSignature Off RewriteCond %{HTTP_USER_AGENT} ^BlackWidow [OR] RewriteCond %{HTTP_USER_AGENT} ^Bot\ mailto:craftbot@yahoo.com [OR] RewriteCond %{HTTP_USER_AGENT} ^ChinaClaw [OR] RewriteCond %{HTTP_USER_AGENT} ^Custo [OR] RewriteCond %{HTTP_USER_AGENT} ^DISCo [OR] RewriteCond %{HTTP_USER_AGENT} ^Download\ Demon [OR] RewriteCond %{HTTP_USER_AGENT} ^eCatch [OR] RewriteCond %{HTTP_USER_AGENT} ^EirGrabber [OR] RewriteCond %{HTTP_USER_AGENT} ^EmailSiphon [OR] RewriteCond %{HTTP_USER_AGENT} ^EmailWolf [OR] RewriteCond %{HTTP_USER_AGENT} ^Express\ WebPictures [OR] RewriteCond %{HTTP_USER_AGENT} ^ExtractorPro [OR] RewriteCond %{HTTP_USER_AGENT} ^EyeNetIE [OR] RewriteCond %{HTTP_USER_AGENT} ^FlashGet [OR] RewriteCond %{HTTP_USER_AGENT} ^GetRight [OR] RewriteCond %{HTTP_USER_AGENT} ^GetWeb! [OR] RewriteCond %{HTTP_USER_AGENT} ^Go!Zilla [OR] RewriteCond %{HTTP_USER_AGENT} ^Go-Ahead-Got-It [OR] RewriteCond %{HTTP_USER_AGENT} ^GrabNet [OR] RewriteCond %{HTTP_USER_AGENT} ^Grafula [OR] RewriteCond %{HTTP_USER_AGENT} ^HMView [OR] RewriteCond %{HTTP_USER_AGENT} HTTrack [NC,OR] RewriteCond %{HTTP_USER_AGENT} ^Image\ Stripper [OR] RewriteCond %{HTTP_USER_AGENT} ^Image\ Sucker [OR] RewriteCond %{HTTP_USER_AGENT} Indy\ Library [NC,OR] RewriteCond %{HTTP_USER_AGENT} ^InterGET [OR] RewriteCond %{HTTP_USER_AGENT} ^Internet\ Ninja [OR] RewriteCond %{HTTP_USER_AGENT} ^JetCar [OR] RewriteCond %{HTTP_USER_AGENT} ^JOC\ Web\ Spider [OR] RewriteCond %{HTTP_USER_AGENT} ^larbin [OR] RewriteCond %{HTTP_USER_AGENT} ^LeechFTP [OR] RewriteCond %{HTTP_USER_AGENT} ^Mass\ Downloader [OR] RewriteCond %{HTTP_USER_AGENT} ^MIDown\ tool [OR] RewriteCond %{HTTP_USER_AGENT} ^Mister\ PiX [OR] RewriteCond %{HTTP_USER_AGENT} ^Navroad [OR] RewriteCond %{HTTP_USER_AGENT} ^NearSite [OR] RewriteCond %{HTTP_USER_AGENT} ^NetAnts [OR] RewriteCond %{HTTP_USER_AGENT} ^NetSpider [OR] RewriteCond %{HTTP_USER_AGENT} ^Net\ Vampire [OR] RewriteCond %{HTTP_USER_AGENT} ^NetZIP [OR] RewriteCond %{HTTP_USER_AGENT} ^Octopus [OR] RewriteCond %{HTTP_USER_AGENT} ^Offline\ Explorer [OR] RewriteCond %{HTTP_USER_AGENT} ^Offline\ Navigator [OR] RewriteCond %{HTTP_USER_AGENT} ^PageGrabber [OR] RewriteCond %{HTTP_USER_AGENT} ^Papa\ Foto [OR] RewriteCond %{HTTP_USER_AGENT} ^pavuk [OR] RewriteCond %{HTTP_USER_AGENT} ^pcBrowser [OR] RewriteCond %{HTTP_USER_AGENT} ^RealDownload [OR] RewriteCond %{HTTP_USER_AGENT} ^ReGet [OR] RewriteCond %{HTTP_USER_AGENT} ^SiteSnagger [OR] RewriteCond %{HTTP_USER_AGENT} ^SmartDownload [OR] RewriteCond %{HTTP_USER_AGENT} ^SuperBot [OR] RewriteCond %{HTTP_USER_AGENT} ^SuperHTTP [OR] RewriteCond %{HTTP_USER_AGENT} ^Surfbot [OR] RewriteCond %{HTTP_USER_AGENT} ^tAkeOut [OR] RewriteCond %{HTTP_USER_AGENT} ^Teleport\ Pro [OR] RewriteCond %{HTTP_USER_AGENT} ^VoidEYE [OR] RewriteCond %{HTTP_USER_AGENT} ^Web\ Image\ Collector [OR] RewriteCond %{HTTP_USER_AGENT} ^Web\ Sucker [OR] RewriteCond %{HTTP_USER_AGENT} ^WebAuto [OR] RewriteCond %{HTTP_USER_AGENT} ^WebCopier [OR] RewriteCond %{HTTP_USER_AGENT} ^WebFetch [OR] RewriteCond %{HTTP_USER_AGENT} ^WebGo\ IS [OR] RewriteCond %{HTTP_USER_AGENT} ^WebLeacher [OR] RewriteCond %{HTTP_USER_AGENT} ^WebReaper [OR] RewriteCond %{HTTP_USER_AGENT} ^WebSauger [OR] RewriteCond %{HTTP_USER_AGENT} ^Website\ eXtractor [OR] RewriteCond %{HTTP_USER_AGENT} ^Website\ Quester [OR] RewriteCond %{HTTP_USER_AGENT} ^WebStripper [OR] RewriteCond %{HTTP_USER_AGENT} ^WebWhacker [OR] RewriteCond %{HTTP_USER_AGENT} ^WebZIP [OR] RewriteCond %{HTTP_USER_AGENT} ^Widow [OR] RewriteCond %{HTTP_USER_AGENT} ^WWWOFFLE [OR] RewriteCond %{HTTP_USER_AGENT} ^Xaldon\ WebSpider [OR] RewriteCond %{HTTP_USER_AGENT} ^Zeus RewriteRule .* - [F] RewriteCond %{REQUEST_METHOD} ^(HEAD|TRACE|DELETE|TRACK) [NC,OR] RewriteCond %{THE_REQUEST} (\\r|\\n|%0A|%0D) [NC,OR] RewriteCond %{HTTP_REFERER} (<|>|’|%0A|%0D|%27|%3C|%3E|%00) [NC,OR] RewriteCond %{HTTP_COOKIE} (<|>|’|%0A|%0D|%27|%3C|%3E|%00) [NC,OR] RewriteCond %{REQUEST_URI} ^/(,|;|:|<|>|â€>|â€<|/|\\\.\.\\).{0,9999} [NC,OR] RewriteCond %{HTTP_USER_AGENT} ^$ [OR] RewriteCond %{HTTP_USER_AGENT} ^(java|curl|wget) [NC,OR] RewriteCond %{HTTP_USER_AGENT} (winhttp|HTTrack|clshttp|archiver|loader|email|harvest|extract|grab|miner) [NC,OR] RewriteCond %{HTTP_USER_AGENT} (libwww-perl|curl|wget|python|nikto|scan) [NC,OR] RewriteCond %{HTTP_USER_AGENT} (<|>|’|%0A|%0D|%27|%3C|%3E|%00) [NC,OR] #Block mySQL injects RewriteCond %{QUERY_STRING} (;|<|>|’|â€|\)|%0A|%0D|%22|%27|%3C|%3E|%00).*(/\*|union|select|insert|cast|set|declare|drop|update|md5|benchmark) [NC,OR] RewriteCond %{QUERY_STRING} \.\./\.\. [OR] RewriteCond %{QUERY_STRING} (localhost|loopback|127\.0\.0\.1) [NC,OR] RewriteCond %{QUERY_STRING} \.[a-z0-9] [NC,OR] RewriteCond %{QUERY_STRING} (<|>|’|%0A|%0D|%27|%3C|%3E|%00) [NC] RewriteRule .* index.php [F] and so on.... <Files .htaccess> Deny from all </Files> <Files .ftpquota> Deny from all </Files>