Apache handlers allow you to control what Apache will do with certain file types. When Apache sees a file, it has an action built in for that file type, and will perform that action.
If you wish Apache to do a different action, you will need to make a handler to tell Apache to perform that action. For example, if you use a file type that requires a special service to run it, such as a file with server side includes that is not named with a .shtml extension, you need to tell Apache to treat these files differently.
To get regular html pages to handle php code, you need to add this line to your htaccess file.
AddHandler application/x-httpd-php5 .html .htm
It is highly recommended that you never allow html pages to automatically handle php or shtml, because this forces all of your html pages to be processed by the server first. Instead, please rename your files to .php or .shtml whenever possible.
System Mime Type defaults
Handler Code File Extensions
application/x-hdf hdf
application/vnd.wap.wbxml wbxml
image/x-xbitmap xbm
image/x-icon ico
image/vnd.djvu djvu djv
application/x-troff-me me
application/perl pl plx ppl perl pm
application/x-tcl tcl
image/bmp bmp
text/x-sql sql
image/png png
text/x-log log
audio/x-realaudio ra
application/x-latex latex
application/x-director dcr dir dxr
text/rtf rtf
application/xhtml+xml xhtml xht
application/vnd.ms-powerpoint ppt
application/x-csh csh
image/svg+xml svg
application/x-troff-ms ms
image/x-rgb rgb
application/x-img img
image/jpeg jpeg jpg jpe
image/x-portable-pixmap ppm
text/plain asc txt
image/cgm cgm
application/x-sh sh
application/andrew-inset ez
application/vnd.wap.wmlscriptc wmlsc
text/x-registry reg
video/vnd.mpegurl mxu
image/ief ief
audio/x-pn-realaudio ram rm
image/x-xpixmap xpm
video/mpeg mpeg mpg mpe
text/tab-separated-values tsv
application/rdf+xml rdf
application/x-httpd-php phtml php php3 php4 php5 php6
x-conference/x-cooltalk ice
image/tiff tiff tif
text/richtext rtx
text/css css
application/ruby rb
application/x-wais-source src
application/xml xml xsl
application/voicexml+xml vxml
image/x-portable-graymap pgm
chemical/x-xyz xyz
model/iges igs iges
application/vnd.mif mif
application/mathml+xml mathml
application/x-ustar ustar
application/x-troff-man man
text/vbscript vbs
text/calendar ics ifb
chemical/x-pdb pdb
application/smil smi smil
application/srgs+xml grxml
image/x-portable-anymap pnm
application/x-shockwave-flash swf
audio/mpeg mpga mp2 mp3
video/x-sgi-movie movie
application/cgi cgi
application/x-cpio cpio
application/x-javascript js
text/x-setext etx
audio/basic au snd
text/sgml sgml sgm
application/x-tar tgz tar
application/vnd.mozilla.xul+xml xul
application/x-futuresplash spl
application/xslt+xml xslt
model/mesh msh mesh silo
application/mac-binhex40 hqx
text/vnd.wap.wml wml
image/x-cmu-raster ras
application/x-sv4cpio sv4cpio
audio/x-aiff aif aiff aifc
application/x-gtar gtar
audio/x-ms-wax wax
audio/x-ms-wma wma
image/x-xwindowdump xwd
application/x-cdlink vcd
application/msword doc
video/quicktime qt mov
application/x-bcpio bcpio
application/x-tex tex
text/x-config cnf conf
application/x-sv4crc sv4crc
application/x-dvi dvi
application/x-troff t tr roff
audio/x-mpegurl m3u
application/x-shar shar
audio/mp4 a-latm m4p m4a mp4
application/pdf pdf
application/mac-compactpro cpt
application/vnd.wap.wmlc wmlc
video/x-msvideo avi
application/ogg ogg
text/html html htm shtml
image/gif gif
audio/midi mid midi kar
application/x-pkcs7-crl crl
application/x-chess-pgn pgn
audio/x-pn-realaudio-plugin rpm
application/srgs gram
application/x-koan skp skd skt skm
image/vnd.wap.wbmp wbmp
application/x-netcdf nc cdf
model/vrml wrl vrml
application/x-httpd-php-source phps
application/vnd.ms-excel xls
application/postscript ai eps ps
application/x-texinfo texinfo texi
application/zip zip
image/x-portable-bitmap pbm
audio/x-wav wav
application/x-x509-ca-cert crt
application/oda oda
application/xml-dtd dtd
application/octet-stream bin dms lha lzh exe class so dll iso dmg
text/vnd.wap.wmlscript wmls
application/x-stuffit sit
