DIFFERENCE BETWEEN HTML AND XHTML

HTML is application of SGML(Standard Generalized  Markup Language).
XHTML is application of XML(eXtensible Markup Language).
HMTL is design to display the data and XHTML is used to design the data.
HTML Requirement : text/html
XHTML Requirement:application/xml

XHTML is derived from html and similar to html , strict rules must be followed in XHTML like closing tags,case sensitive(lowercase),must have proper tags and nesting must be properly closed.

Main differences is

• Case Sensitive
• Optional tags
• Properties of Root Element

CILENT-SERVER SIDE SCRIPTING LANGUAGES

CILENT SIDE SCRIPTING LANGUAGES(EMBEDDED SCRIPT):

• HTML(HYPERTEXT MARKUP LANGUAGE)
• CSS(CASCADING SYTLE SHEET)
• DHTML(DYNAMIC HYPERTEXT MARKUP LANGUAGE)
• JAVA SCRIPT

SERVER SIDE SCRIP ING LANGUAGES:

• ASP (ACTIVE SERVER PAGE)
• PHP
• JAVA
• SERVERSIDE SCRIPTING
• PERL
• JSP(JAVA SERVER PAGES)
• RUBY 
• PHYTHON
• SML(SERVER MACRO LANGUAGE)
• LASSO
• COLD FUSION MARKUP LANGUAGES
• WEB DNA
• LUA(LIGHT WEIGHT MULTIPROGRAMMING LANGUAGES)