These days, vast portions of the internet are dedicated to online shopping and financial transactions. It wasn’t always this way though. Back when sites like Amazon.co.uk were beginning to sell books online, making purchases over the internet was a brand new and unexplored territory.
Now though, setting up an online shop with secure payment facilities is relatively straightforward, with a lot of the hard work taken on by payment gateways and merchant accounts.
Payment gateways and merchant accounts
The services which do the heavy lifting when it comes to taking online payments are the merchant accounts and the payment gateways.
A merchant account can usually be obtained through your own bank, normally requiring no significantly complex set up.
The payment gateway is the service which provides the communication between your website & shopping cart software and your acquiring bank’s merchant account, checking with the relevant credit or debit card providers along the way (e.g. Visa, Mastercard etc).
Popular payment gateways include Worldpay and Stripe.
All of the transactions take place over secure connections, and in such a way that you aren’t personally responsible for ensuring the safety of your customer’s credit card details.
This process takes only seconds, and once complete, if the transaction is successful, your website’s shopping cart software will record the sale, notify the customer of their purchase via email, notify yourself via email of this new order and redirect the customer to a landing page of your choosing.
Open-source shopping cart solutions
The software which powers the shop itself too, has evolved dramatically since the early days of online shopping. It used to be that e-commerce software was complex and required a great deal of work to tailor to your requirements.
If your site runs on Wordpress, a popular choice of e-commerce platform is WooCommerce. WooCommerce is a highly capable and robust online shopping cart provided as a Wordpress plugin, to enhance and complement the core Wordpress functionality.
Online sales in Europe in 2015 totalled £156 billion, an 18% increase over the year before 
It’s a very thorough system, and can provide a range of options for products, from dynamic variable products, downloadable products, virtual products (e.g. services & consultation) etc.
As well as being a plugin itself, there are additional further plugins that can enhance WooCommerce’s own core functionality, adding on the potential for different payment providers, shipping companies, extra functionality and more.
Statamic also has a capable, yet simpler e-commerce solution named Bison. This may be of interest for smaller shops with fewer complex product requirements, and like Wordpress/WooCommerce, Bison integrates fully with the core website code, providing a seamless and enjoyable online shopping experience for your visitors.
Do it your way
For e-commerce projects with very specific requirements, there’s also the option to build completely bespoke shopping cart functionality on top of a framework such as Laravel (see this article for an outline of frameworks vs. CMSs) - meaning that you aren’t tied into a specific e-commerce solution’s structure or process.
If you’d like to discuss e-commerce requirements in more detail, or if you already have an idea or outline for your project, get in touch and we can talk further.
 source: http://www.retailresearch.org/onlineretailing.php