The number of USB ports on a motherboard varies widely depending on the model and form factor, but a typical modern motherboard usually provides:

• Around 6 to 10 USB ports in total, combining rear I/O ports and internal headers for front panel connections.
• For example, a Gigabyte B450M-DS3H motherboard offers 2 USB 3.1 Gen 1 ports via an internal header and 8 USB 2.0/1.1 ports (4 on the back panel and 4 via internal headers), totaling around 10 USB ports

• Many motherboards have multiple USB headers inside the case, each header usually supports two USB ports, allowing front panel USB connectors on the case to be connected

• High-end or newer boards, like some Z790 chipset models, can have up to 8 USB-A and 2 USB-C ports on the rear I/O plus additional internal headers, resulting in more than 10 ports total

In summary, a typical motherboard supports at least 6 to 10 USB ports, including both rear panel ports and internal headers for front panel USB ports. You can also expand USB connectivity using USB hubs or PCIe USB expansion cards if needed