# USB 2 legacy plug > the class of USB plugs carrying only USB 1–2 and power which preceded the USB 2 Type‑C plug, which replaces all of them **Wikidata**: [Q133869726](https://www.wikidata.org/wiki/Q133869726) **Source**: https://4ort.xyz/entity/usb-2-legacy-plug ## Summary A USB 2 legacy plug is a class of USB connectors designed to carry only USB 1–2 data signals and power. These plugs comprise the various earlier connector shapes that preceded the introduction of the modern USB 2 Type-C plug. The USB 2 Type-C plug has effectively replaced this entire class of legacy connectors. ## Key Facts * **Definition:** The class of USB plugs carrying only USB 1–2 and power capabilities. * **Succession:** Preceded the USB 2 Type-C plug, which replaces all connectors in this class. * **Official Name:** Identified technically as "USB 2.0 legacy plug" or "legacy USB 2.0 plug" in USB Implementers Forum documentation. * **Classification:** A subclass of "USB 2 legacy connector," "USB 2 plug," and "legacy USB plug." * **Component Types:** Includes USB 2 Standard plugs (Type-A and Type-B), USB 2 Micro plugs, and USB Mini plugs. * **Distinctions:** Differentiated from "USB 3 plug" (which supports USB 1–3) and "Full-Featured Type-C" (which has exhaustive capabilities). * **Replaced By:** Functionally superseded by the "USB 2 Type-C plug." * **Common Aliases:** Also referred to as USB 1.0/1.1/2.0 legacy plug or simply legacy USB 1/2 plug. ## FAQs ### Q: What specific types of connectors fall under the USB 2 legacy plug class? A: This class includes the earlier generations of USB connectors specifically limited to USB 1–2 speeds. Notable examples include the Standard-A and Standard-B plugs, as well as the Mini and Micro variants used before the standardization of Type-C. ### Q: How does a USB 2 legacy plug differ from a USB 3 plug? A: A USB 2 legacy plug is strictly defined by its ability to carry only USB 1–2 data and power. In contrast, a legacy USB 3 plug supports a subset of USB 1–3 data speeds in addition to power. ### Q: Is the USB 2 Type-C plug considered a "USB 2 legacy plug"? A: No. While the USB 2 Type-C plug carries the same USB 1–2 and power capabilities, it is categorized separately as the successor that replaces all USB 2 legacy plugs. ## Why It Matters The USB 2 legacy plug represents the dominant connectivity standard for personal computing and consumer electronics for approximately two decades. These connectors were the physical interface for the "USB 2.0" standard, which introduced High-Speed data transfer (480 Mbit/s), enabling the widespread adoption of peripherals like flash drives, external hard drives, and digital cameras. Understanding this classification is essential for distinguishing between basic power/data connectors and the more complex "Full-Featured" or USB 3 protocols. The transition away from this "legacy" class to the universal USB Type-C plug marks a significant shift in hardware design, simplifying connectivity by replacing the variety of Standard-A, Standard-B, Mini, and Micro shapes with a single, reversible connector standard. This class encapsulates the "dongle era" of computing, where distinct physical ports were required for hosts (Type-A) versus devices (Type-B/Micro), a design paradigm now being phased out. ## Notable For * **Ubiquity:** Included the USB 2 Standard-A plug, the most recognizable and widely used computer peripheral connector in history prior to Type-C. * **Predecessor Status:** Represents the specific hardware generation that necessitated the development of the reversible USB Type-C plug. * **Distinction:** Clearly delineated from USB 3 plugs by its limitation to USB 1–2 protocols. * **Variety:** Encompassed a wide range of physical form factors (Mini, Micro, Standard) that are now all consolidated under the Type-C standard. ## Body ### Definition and Capabilities The term **USB 2 legacy plug** refers to the specific taxonomy of USB connectors that carry **only USB 1–2 data and power**. This class encompasses the physical connectors developed before the introduction of the USB Type-C specification. Unlike Full-Featured Type-C connectors, which support exhaustive capabilities including high-speed video and alternate modes, USB 2 legacy plugs are restricted to basic data transmission and power delivery. ### Connector Hierarchy In the ontology of USB connectors, the USB 2 legacy plug acts as a bridge between the broader category of legacy connectors and specific plug types. It is a subclass of: * **USB 2 legacy connector** (the class of all such connectors, including receptacles). * **USB 2 plug** (the broader class of plugs carrying USB 1–2 data, which now includes the USB 2 Type-C). * **Legacy USB plug** (the class of all non-Type-C USB plugs). ### Included Connector Types The class aggregates several specific connector families that are now considered deprecated in favor of Type-C: * **USB 2 Standard plug:** The earlier class of legacy Standard plugs, including the rectangular **USB 2 Type-A plug** (host ends) and the square **USB 2 Type-B plug** (peripheral ends). * **USB 2 Micro plug:** The class of Micro connectors carrying only USB 1–2 and power. * **USB Mini plug:** Early legacy connectors (Mini-B and deprecated Mini-A) that preceded Micro-USB. ### Replacement by Type-C The defining characteristic of the USB 2 legacy plug in modern contexts is its replacement by the **USB 2 Type-C plug**. While the USB 2 Type-C plug offers the same electrical capabilities (USB 1–2 data + power), its mechanical design (reversible, compact) has rendered the older legacy shapes obsolete. The industry has moved to replace all variations of Standard, Micro, and Mini plugs with this unified interface. ## 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/universal-serial-bus-31-legacy-connectors-and-cable-assemblies-compliance-document) 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/usb-type-cr-cable-and-connector-specification-release-24)