The Wikipedia article USB hardware states:
Standard connectors
- The type-A plug. This plug has an elongated rectangular cross-section, inserts into a type-A receptacle on a downstream port
on a USB host or hub, and carries both power and data. Captive cables
on USB devices, such as keyboards or mice, terminate with a type-A
plug.- The type-B plug: This plug has a near square cross-section with the top exterior corners beveled and inserts into a type-B receptacle on
an upstream port on a USB device, such as a printer. On some devices,
the type-B receptacle has no data connections, being used solely for
accepting power from the upstream device. This two-connector-type
scheme (A/B) prevents a user from accidentally creating a loop.
Best Answer
The USB 'receptacle' is the mechanical connector - the thing you plug a USB cable into. That consists of electrical contacts in a plastic-and-metal housing.
The USB 'port' describes the connector, communication electronics, software and any power supply electronics needed by the equipment the port is in.
For a PC, the USB port uses a connector, power supply with current control/protection, communications electronics and an OS software driver.