A website presents the business: pages, products, stories, contact. People arrive, read, and sometimes enquire. That is still the right shape for many companies.
A web application is software delivered in the browser. People sign in, complete jobs, configure products, manage members, or run an operation. The interface is a tool, not a brochure.
E-commerce sits in the middle. A simple catalogue can be a website. Trade pricing, accounts, parts lookup and custom checkout are application work wearing a storefront.
The mistake is commissioning a website when the real requirement is software, or commissioning a platform when a clear site would do. Cost and timeline follow that distinction.
If the public face needs to do more than a template allows — catalogues, accounts, configuration, member areas — see websites and e-commerce. If the work is internal or product-shaped, see software development. If the problem is systems that do not talk, see integrations.