This feature is very helpful and millions of users have become used to with it.
So, all in all, these red-green wavy underlines indicate spelling and grammar mistakes. For grammatical errors a wavy green line appears under the word or phrases.
If there is a spelling mistake, the word gets underlined with a red color wavy / squiggly / zig-zag line indicating the error. World’s most popular word processing software, MS Word, can check your text for correctness and allows you to make amends. Microsoft Word comes with a powerful spelling and grammar checking module.
