The web developer is in charge of designing sites, applications, software and computer programmes “tailored” to meet the needs of their company or customers (using an Open Source – WordPress, PrestaShop, Magento, Drupal, Odoo, etc. or creating a site from scratch).
Software as a Service (SaaS) is a software distribution model in which a third-party provider hosts applications and makes them available to its customers over the Internet. This refers to sites made with SquareSpace, Wix, Shopify, Contentful, Tilda, BigCommerce, etc.