Is HTML case-sensitive or case-insensitive?

Is HTML case-sensitive or case-insensitive?

Generally, HTML is case-insensitive, but there are a few exceptions. Entity names (the things that follow ampersands) are case-senstive, but many browsers will accept many of them entirely in uppercase or entirely in lowercase; a few must be cased in particular ways.

XHTML , that is being XML is case sensitive. Generally, HTML is case-insensitive, but there are a few exceptions. Entity names (the things that follow ampersands) are case-senstive, but many browsers will accept many of them entirely in uppercase or entirely in lowercase; a few must be cased in particular ways