# USB 3 Standard connector > the latter class of legacy (pre-C) USB Standard connectors **Wikidata**: [Q133871688](https://www.wikidata.org/wiki/Q133871688) **Source**: https://4ort.xyz/entity/usb-3-standard-connector ## Summary The USB 3 Standard connector is a class of legacy USB connectors that preceded the introduction of the USB-C standard. It is officially designated as the USB 3.1 Standard connector and serves as the subsequent class following earlier USB standards. This category encompasses distinct form factors including Standard-A and Standard-B, available as both plugs and receptacles. ## Key Facts * **Official Name:** USB 3.1 Standard connector. * **Aliases:** USB 3.0 Standard connector; USB 3.1 Standard connector. * **Classification:** A subclass of both the "USB 3 connector" and the "USB Standard connector" classes. * **Successor Status:** Represents the "latter" class of legacy Standard connectors, distinct from earlier USB 2 Standard connectors. * **Form Factors:** Includes the USB 3 Standard-A connector (host end) and USB 3 Standard Type-B connector (peripheral device end). * **Component Types:** Comprises both plugs and receptacles. * **Distinct From:** Differentiated from the USB 3 Micro connector and the USB 2 Standard connector. * **Historical Context:** Categorized as "legacy" or "pre-C" hardware, preceding the USB-C specification. ## FAQs ### Q: What is the difference between a USB 3 Standard connector and a USB-C connector? A: The USB 3 Standard connector is classified as a "legacy" or "pre-C" connector, meaning it represents the older generation of hardware that existed before the USB-C standard was introduced. ### Q: Does the USB 3 Standard connector include different plug types? A: Yes, this class includes specific types such as the Standard-A (typically for the host) and Standard-B (typically for the peripheral device), available in both plug and receptacle formats. ### Q: Is the USB 3 Standard connector the same as the USB 2 Standard connector? A: No, they are distinct classes. The USB 3 Standard connector is the "latter" class that followed the USB 2 Standard connector, though both are considered legacy Standard connectors that preceded USB-C. ## Why It Matters The USB 3 Standard connector represents a critical phase in the evolution of peripheral connectivity, serving as the primary interface for high-speed data transfer immediately prior to the industry-wide transition to USB-C. As the "latter class" of legacy connectors, it bridged the gap between earlier USB 2.0 technologies and the modern reversible connector standard, maintaining the classic "Standard" form factor (the familiar rectangular A-plug and square-ish B-plug) while supporting updated specifications. This connector class is significant because it proliferated widely under the USB 3.0 and USB 3.1 specifications, becoming the standard for desktop computers, laptops, and hard drives for years. Understanding this entity is essential for distinguishing between the older, directional "Standard" form factors and the modern USB-C, as well as differentiating the higher-speed USB 3 generation from the preceding USB 2 Standard connectors. ## Notable For * Being the immediate predecessor to the modern USB-C connector in the Standard form factor lineage. * Encompassing the "Powered-B" variant, which added extra pins for power delivery, alongside the standard A and B types. * Retaining the directional, non-reversible design of legacy USB hardware, in contrast to the reversible USB-C. * Serving as the physical interface for USB 3.0 and USB 3.1 protocols before the specification shift to Type-C. * Distinction as the "latter class" of the USB Standard family, superior to but eventually replaced by Type-C. ## Body ### Classification and Hierarchy The USB 3 Standard connector is taxonomically defined as a subclass of the broader "USB 3 connector" and "USB Standard connector" classes. It is categorized specifically as "legacy" hardware, a term used to describe the generation of connectors that immediately preceded the current USB-C standard. This class sits alongside other form factors like Micro and Mini but is distinct from them. ### Connector Types and Variants This entity covers several specific hardware implementations defined by the USB 3.0 and 3.1 specifications: * **Standard-A:** Defined as the host end of the connection. * **Standard Type-B:** Defined as the peripheral device end. * **Powered-B:** An advanced variant included in this class (visible in technical illustrations of the set), designed to support additional power delivery. * **Plugs and Receptacles:** The class encompasses both the male (plug) and female (receptacle) components for these types. ### Nomenclature and Evolution While commonly referred to as the "USB 3 Standard connector," official documentation cites the value as the "USB 3.1 Standard connector." It is also aliased as the "USB 3.0 Standard connector," reflecting the evolution of the USB specification names (3.0 to 3.1) while the physical "Standard" form factor remained largely consistent. It is explicitly differentiated from the "USB 2 Standard connector," indicating a generational leap in speed and capability within the same physical family, and from the "USB 3 Micro connector," which shares the generation but differs in size and shape. ## 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)