WooCommerce

WooCommerce is an open-source ecommerce plugin for WordPress, made by Automattic (the same company behind WordPress.com). It turns an ordinary website into a full online store and is today the most-used ecommerce software in the world. It suits freelancers, small businesses and growing brands that want their shop fully under control and don't want to be locked into a closed platform.

It works like this: you install WordPress, add the WooCommerce plugin and start uploading products. You enter names, prices, photos, variants (sizes, colours) and stock. A customer adds items to the cart and pays through a connected payment gateway. In a clear admin dashboard you see orders, revenue, stock levels and sales reports, so you have an instant overview of what's happening in your shop.