The WordPress software itself is free to use, as it’s an open-source project. However, there are costs associated with running a business website on WordPress. These costs include domain registration, web hosting, and may also include premium themes or plugins, and potentially developer fees if you hire someone for design or maintenance.  It’s also worth noting that there’s a difference between WordPress.org, the free, open-source software, and WordPress.com, a for-profit service that offers free basic hosting with optional paid plans.