White Hat/Black Hat/Gray Hat
White Hat/Black Hat/Gray Hat – These are common terms used in the computing world to refer to the level of ethics involved in certain SEO or hacking tactics.
White Hat SEO techniques – Ethical SEO techniques
Black Hat SEO techniques – techniques that are unethical and attempt to circumvent rules and regulations that are in place.
And you guessed it, "Gray Hat" falls somewhere in the middle.