Ecommerce is the process of accepting a payment over a website. This process can take on a variety of forms (retail, donations, payment for services, etc...) but the setup requirement to take these payments remains similar. Outlines below are the technical and administrative components required to complete transactions online.
The fist step to setting up a successful ecommerce project is to establish internet merchant account. Most banks now offer internet merchant accounts through their small business departments. There are normally fees associated with these types of accounts and these should be reviewed by the client before hand.
A credit card gateway is required to process credit card transactions. The gateway component does the actual communication with the credit card issuer systems completing either a pre-authorization, sale or post-authorization transaction. Depending on the nature of your business, the gateway will be configured accordingly. These gateways also charge a nominal fee, normally based on a percentage/usage rate card.
An SSL Certificate (CRT File) is purchased through a third party security provider such as VeriSign.com or Thawte.com. The certificate will require a validation procedure and detailed business information to be purchased properly. Once purchased, the certificate must be installed on the hosting server.