Spell checker is a tool that helps users to find errors in their writings. It usually operates automatically after you activate it and highlights possible errors so that you can see them more easily. This is a time-saving feature, as it can identify mistakes that you may have missed.
Generally, spell checking uses algorithms that compare every word you type to thousands of correctly spelled words in a dictionary file. It also checks for punctuation and grammatical rules.
The best spell checkers use a combination of these technologies and morphologic algorithms to handle alternative forms of words used in different grammatical scenarios. In addition, some of them have built-in spellcheckers for homonyms, which are words that sound similar but have different spellings and meanings.
A spell checker identifies words that have been spelled incorrectly and gives you a choice between correcting them or adding them to the dictionary. The option is often accompanied by a description of the mistake, which can help you understand why it was detected as an error and how to avoid repeating it in future.