whitehat means promoting stuff the legal way and not breaking any promotion rules.

Black hate SEO is that, when you are performing the task, which is not allowed by Google algorithm. And When you are following the rules and rugulation, its called white hate seo.

White Seo is promoting your site acording to search engines rules. This will get you in top of search results.
How many things or techniques are included in it?
Nothing is really clear ( except what not to do ) so the range is quite big. However if what you do can help a visitor ... then is white.

Whitehat SEO is the process to obey all the rule of the Search engines, it regards the human readers as the centre and doing all to attract and satisfy them by useful information from the sites

In white hat SEO you must follow the Google search engine rules and algorithm.

Doing onpage and offpage activities in ethicle way is called white hat SEO.

Hello...
white hat seo is an ethical way with the help of which we can appear on top postion of SERPs by following all the Guide lines made by search engines.We should follow all the updates that are made by Google so that we know about all the updates and we can follow them...
Thnx..:)