# USB Standard-B connector > a class of legacy USB connectors (peripheral device end) that preceded USB-C **Wikidata**: [Q133871019](https://www.wikidata.org/wiki/Q133871019) **Source**: https://4ort.xyz/entity/usb-standard-b-connector ## Summary The USB Standard-B connector is a class of legacy USB connectors located at the peripheral device end of cables. It predates the modern USB-C standard and serves as the interface typically found on devices such as printers and hard drives, rather than on host computers. ## Key Facts * **Definition:** A class of legacy USB connectors designed for the peripheral device end of a cable. * **Succession:** It is a legacy interface that preceded the USB-C (Type-C) standard. * **Variations:** The class includes specific versions such as the USB 2 Standard-B connector and the USB 3 Standard-B connector. * **Components:** It encompasses both plugs (male) and receptacles (female). * **Also Known As:** Standard USB-B connector. * **Distinct From:** It is different from the USB Standard-A connector, USB Micro-B connector, and USB Mini-B connector. * **Classification:** It is a subclass of the USB Standard Type-B connector. ## FAQs ### Q: What is the primary use of the USB Standard-B connector? A: The USB Standard-B connector is designed to attach to the peripheral device end of a USB cable (the device side), as opposed to the host or computer side. ### Q: Is the USB Standard-B connector current technology? A: No, it is classified as a legacy connector. It has been succeeded by the USB Type-C connector standard. ### Q: What is the difference between USB Standard-B and USB Standard-A? A: The Standard-B connector is used on peripheral devices, while the Standard-A connector is used on the host controller (computer). ## Why It Matters The USB Standard-B connector represents a critical phase in the evolution of peripheral connectivity. Before the adoption of the reversible and universal USB-C, the Standard-B interface was the industry standard for connecting large peripheral devices, such as printers, scanners, and external drives, to host computers. Its design served a functional purpose: the distinct shape of the Type-B connector compared to the Type-A prevented users from incorrectly looping the network or connecting two hosts directly without a specific crossover cable bridge. While the USB 2 Standard-B version carried only USB 1–2 signals and power, the USB 3 Standard-B iteration expanded these capabilities to handle higher data transfer rates, though both have now been effectively replaced by the USB Type-C standard in modern devices. ## Notable For * **Peripheral Interface:** Being the standard interface for the "device" end of USB cables for decades. * **Legacy Status:** Serving as the immediate predecessor to the modern USB-C connector. * **Distinct Hierarchy:** Existing as a specific subclass with distinct USB 2 and USB 3 variations (Plug and Receptacle). * **Standardization:** Being formally defined by the USB Implementers Forum in legacy cable and connector specifications. ## Body ### Classification and Hierarchy The USB Standard-B connector is formally classified as a subclass of the "USB Standard Type-B connector." It encompasses the physical interfaces used to connect peripheral devices to hosts. Within this class, there are distinct categories for the plug (male end) and the receptacle (female port). ### Technical Variants The knowledge entry distinguishes between several key iterations of the Standard-B connector: * **USB 2 Standard-B connector:** Described as the largest of the legacy USB 2 connectors. It is capable of carrying USB 1–2 signals and power. This specific variant has been functionally replaced by USB 2 Type-C connectors. * **USB 3 Standard-B connector:** A class of legacy connectors that also fits the Standard-B form factor but is designed for the USB 3.0 standard and higher speeds. ### Relationships to Other Connectors The USB Standard-B is strictly differentiated from other USB form factors. It is distinct from the **USB Standard-A connector** (which serves the host end) and smaller variants like the **USB Micro-B** and **USB Mini-B** connectors, which were typically used for mobile devices. ### Official Specifications The connector is officially referenced in key USB specifications, including: * USB 3.1 Legacy Cable and Connector Revision 1.0 * USB Type-C Cable and Connector Specification Release 2.4 * USB 3.2 Revision 1.1 ## References 1. [Source](https://www.usb.org/document-library/usb-31-legacy-cable-and-connector-revision-10) 2. [Source](https://www.usb.org/document-library/usb-type-cr-cable-and-connector-specification-release-24) 3. [Source](https://www.usb.org/document-library/usb-32-revision-11-june-2022) 4. [Source](https://www.usb.org/document-library/usb-type-cr-connectors-and-cable-assemblies-compliance-document-rev-21b) 5. [Source](https://www.usb.org/document-library/universal-serial-bus-31-legacy-connectors-and-cable-assemblies-compliance-document)