Ecommerce, short for electronic commerce, refers to the buying and selling of goods and services over the internet. It encompasses a wide range of activities including:

1. Online Retailing: Businesses selling products directly to consumers through websites or online platforms. Examples include Amazon, eBay, and Shopify stores.
2. B2B Transactions: Businesses selling products or services to other businesses. This can include wholesale suppliers, manufacturers, and service providers.
3. Digital Products and Services: Selling products that exist only in digital form, such as software, ebooks, and online courses.
4. Online Marketplaces: Platforms where multiple sellers list their products or services, such as Etsy or Alibaba.
5. Subscription Services: Companies offering products or services on a recurring basis, such as streaming services (Netflix) or subscription boxes (Birchbox).
6. Payment Gateways: Technology that processes payments online, such as PayPal, Stripe, or Square.

Ecommerce has grown rapidly due to advancements in technology, increased internet access, and changing consumer preferences. It allows businesses to reach a global audience, offers consumers convenience, and provides various tools for managing sales, marketing, and customer service.