In its simplest terms, Ecommerce or E-commerce or eCommerce – how ever which way the word shows up, is an interchange of goods or commodities (products or services) that is very similar to any kind of commerce that exists. It differs from the other types of commerce such as foreign commerce and domestic commerce on only two attributes. One, ecommerce can be both accomplished on foreign and domestic scales; and two, it accommodates every kind of trader, from those trading in small, medium and large scale businesses, to those in micro businesses.
Foreign and domestic commerce both happens on a large scale basis. Foreign commerce is between different countries, while domestic commerce happens with business entities between different parts of the same country.
http://ecommerceevolution.blogspot.com/2009/10/maintain-online-customers.html is a fusion of the words “electronic” and “commerce.” This basically means that all transactions happen over the electronic systems like the Internet or other computer networks - a good example of which is stock brokering, where most of the transactions from bidding to selling can happen via computer links inside and outside the stock markets.