A spell checker compares every word in the document with its dictionary thesaurus word list( dictionary, thesaurus, word list ).
Spell checkers do not check the meaning context use( meaning, context, use ) of the word.
Spelling errors are often highlighted with a green wavy line.
A thesaurus is useful for punctuation errors.
Spell checkers do not always find spelling mistakes because
every country has their own unique way of spelling e.g. color (US), colour (AUS) and it depends on the spell checker's dictionary.
if the word is in its' dictionary then it is correct.
it does not look at meaning.
