Seo stands for Search engine optimization.Seo is art of ranking in the search engines.Let learn Seo types and their categories.
Types of SEO :

So Basically There are Three ways of doing Seo ?
What is
On-Page Seo?
On-Page Seo: On-page, SEO process includes on-site work like titles, description, keywords tags, image tags, alt tags, caption, image description, keyword research, competitor analysis, and a good selection of keywords for your website.

Off-page Seo?
Off-page Seo: Off-page SEO process includes off-site work which includes link building, creating backlinks for your website which will increase the link popularity of your website through activities like guest posting, link exchange, social bookmarking, and more.

Technical Seo?
Technical Seo: Technical Seo process includes website & speed optimization, creating XML sitemaps and robots.txt, website UI /UX, website structure which helps google to crawl and index rapidly at search engines.

Seo tactics and methods :
Seo techniques are classified into Four broad categories :

White Hat Seo :
Techniques that google, bing, and yahoo search engines recommend as part of good design and good tactics of Seo which improve ranking at search engine result pages as per guidelines referred to as white hat SEO.
Black hat Seo :
Techniques that google, bing, and yahoo search engines do not approve and attempt to minimize the effect of Seo and ranking increase through manipulation tactics referred to as black hat Seo.
Gray Hat Seo :
Techniques which are combination of white hat Seo and blackhat seo are majorly used by seo agencies for quick results reffered to as gray hat Seo.
Negative Seo :
A technique used for deranking competitors’ websites and making them suffer to lose all ranking on a google search engines is referred to as negative SEO.

Different types of Seo :
Local Seo :
Local search engine optimization is concerned with optimizing your website for local consumers, especially for localized consumers within a specific geographic location. The usage of keywords and phrases that are specific to your geographic location as well as specific phrases related to that location. Because this type of marketing tends to be more targeted, many experts consider it to be more effective than other forms of marketing.
International Seo :
The International Seo process starts with optimizing your website worldwide with multilingual SEO which targets different countries’ search engines on the web.
Enterprise Seo :
To perform seo of million of pages or webpages of enterprise or gaint business company website enterpise seo are been done .
Ecommerce Seo :
E-commerce SEO is performed at the online stores to make them visible on SERP pages to get more sales on the website through a particular search of keywords. It will help your website to get genuine and potential customers through the web. E-commerce website Seo is necessary for every business.
Content Seo :
Content Seo or Blogging Seo can generate more organic traffic for your website or blogging website which can turn your business into 10 x. Basically, Content Seo performed on articles of the website which include different practices like creating ctr title, Heading, keywords, faqs, images, and more.

Video Seo :
Videos Seo process is performed simply by optimizing your videos to rank on search engines on targeted keywords for specific categories or niches to build an audience on our youtube channel or drive more traffic on the website.
Mobile Seo :
Mobile Seo process is performed on the website for smartphones and mobile phones better visibility and to achieve your website content become more user friendly to read and get good experience.

Simple way to understand different types of Seo.