A website is set of web pages hosted by web server (Web Domain). Types of website?(This question should be remove) Static sites & Dynamic sites.
A static website or web page whose content is fixed (does not change or has to be manually changed)
A dynamic website or web design made from computer program its content can be update using database. A dynamic web design include lot of features in your website. It content can be updated using CMS.
The responsive web site technology helps the website to adjust in different screen size & resolution, so it become easy to view in all the devices & different screen resolution.
CMS is computer program allows you to edit, modify & update your website content using a central interface.
To buy & sell products over the Internet then it need to be done through E commerce website.
A portal is like web application where you can find the all the product & services information within one site.
A web application that runs using a web browser. It can a computer program also which need a web browser to run a program.
SEO[Search Engine Optimization] helps to increase the website traffic and page rank.It helps to increase the website popularity and website income. SEO plays a vital role in website success.Everyone must implement SEO service for their sites.So that they can successfully run their website on internet.
SMO, social media optimization is the process of increasing the awareness of a product, brand or event by using a number of social media network like facebook, twitter, linked in & many more.
In this demand world when you want to expand your business, a website can do much more for you and at a much lower cost.