What is Ecommerce Website? How to Build an ECommerce Website?

eCommerce website is nothing much different from a physical marketplace that is engaged in sell and purchase process.
the only difference i can tell you in this post and make it easy for you to know is that eCommerce website gives you more control and reach than a physical marketplace or store. 
Advertisers, Publishers and Affiliates are 3 primary elements of the whole process.
Here you might wanna look and find what you are looking for.

Electronic commerce or ecommerce is a term for any type of business, or commercial transaction, that involves the transfer of information across the Internet. It covers a range of different types of businesses, from consumer based retail sites, through auction or music sites, to business exchanges trading goods and services between corporations. It is currently one of the most important aspects of the Internet to emerge.

Ecommerce allows consumers to electronically exchange goods and services with no barriers of time or distance. Electronic commerce has expanded rapidly over the past five years and is predicted to continue at this rate, or even accelerate. In the near future the boundaries between "conventional" and "electronic" commerce will become increasingly blurred as more and more businesses move sections of their operations onto the Internet.

Steps for building an Ecommerce Website:-

1. Decide on your product.

2. Set your pricing.

3. Research shipping costs and options.

4. Choose your eCommerce web hosting.

5. Pick a domain name and brand.

6. Build your eCommerce website

7. Set up a merchant account. Get your SSL certificate