Good SEO method can be done by using white hat technique to improve the website position in the SERP. Bad SEO method is that you use black hat technique to get better position in the SERP.

Hi everyone,
      Good SEO is the "correct" way of optimizing your website so it shows up in search.
      Bad SEO is using tactics for search engine optimization that are generally regarded as spammy, dishonest, or otherwise "bad."

White-hat SEO is good SEO and Black-hat SEO is bad SEO which is the way where spam lists gets increased. Black-hat SEO or bad SEO are the way of violating the submission guidelines of search engine.

If we are going to follow all the rules of Google then we are doing good seo and if we dont then we are doing bad seo.So we should aware about all the updates made by Google so that we can follow all the guide lines and can do good seo....

types of seo:

The seo is of 2types
1.White Hat Seo and 
2.Black Hat Seo

White hat seo is ethical way of optimizing search engine it needs lot of time and care.Its safe for your sites.
Black hat seo is inorganic method to gain high rankings in the search engine result pages.Its a risky factor.

Black hat seo is bad and not that much helpful. Always use white hat seo techniques.

Good SEO gives you results and bad SEO gives you nothing )

if we do seo in natural way using ettical technique or white hat technique that is good seo.
if we do seo in unnatural way using unetticar technique or black hat technique that is called as bad seo.it's actualy against to the google guidlines and we are cheating to the search engine so it's not a right manner to do seo.

Good SEO is pure white hat ethical SEO Technique whereas bad SEO is unethical way of SEO with keyword stuffing, cloacking, door way pages creation etc.

if you will do seo  with white hate method  than it will take time and ranking will stable if you will do seo with black hat then ranking will come fast but not stable

black hat seo is bad.

White Hat and Black Hat, the both ways of SEO marketing. As the name indicates, White is good and Black is bad because of White hat SEO obeys Search engine rules. It's one of authentic way for the brand promotion. It's time consumed but safe way to getting huge traffic and brand identification while Black hat doesn't consider Search Engine rules and regulation. It could be dangerous for the site. We never use Black Hat Techniques.

Good seo mean white hat seo which we use simple and correcy ways of seo according to search engine rules. But in bad seo we use some shortcut for quick search.

Good SEO
Putting together a combination of soaring search volume keywords along with long tail keyword phrases and also some low search volume keywords elegantly and strategically through your website.
Bad SEO
Simply going after one word keyword for each page of your website eager you will be at the top of the search results for only high search volume keywords.

There is two types of SEO, i.e. white hat SEO and black hat SEO. White hat SEO is good one and is preferred by Google. Black hat SEO is BAD SEO and which is not allowed by Google.

Good SEO is pure white hat SEO techniques this is the best for better website promotion and bad SEO is black hat SEO which is not helpful for website promotion for a long time.

To be short about seo, natural links are good seo and un-natural links are bad seo.

Good SEO is pure ethical white hat SEO whereas bad SEO is usage of keyword stuffed and bad links from other websites.

White hat SEO is using white hat techniques that strictly follows search engines guidelines whereas in black hat SEO its primary target is search engines and not human audience anymore.