in my main site ó is showing as it is.
But in applications of this site like in bebo.com it is showing as ?.
what is difference between ó and ó
plz help.

what is difference between ó and ó

the character set that the page is set to use.

HTML entities should always show as the intended display characters, but the display of ASCII values in the source will depend on what the page character set is designated as.

is about the Content-Type charset [META-stuff] or, like chrishirst says "the character set that the page is set to use".

find the set where the char is from