Web design focuses on how the site communicates visually and how users experience the page. Web development focuses on how the site works, including code, templates, CMS structure, integrations, performance, and technical functionality.
Web design usually focuses on the visual and experiential side of a website. That includes layout, typography, color, imagery, hierarchy, navigation, and how visitors understand the page.
Web development focuses on making the site function. That may include HTML, CSS, JavaScript, CMS templates, modules, forms, integrations, performance, security, and other technical requirements.
For a business website, both need to be guided by strategy. A beautiful site can still fail if the message is unclear, and a technically solid site can still underperform if the user experience does not support the buyer journey.