Introduction
When someone asks, “What’s the difference between USB-A, B, C and USB 2.0, 3.0, 4.0?”, it often causes confusion. The key is that USB‑A/B/C refers to physical connector types, while USB 2.0/3.0/3.1/3.2/4.0 refers to the underlying protocol version—each with different speed and power capabilities. Let’s dive in.
Connector Types: USB‑A, USB‑B, USB‑C
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USB‑A: The classic rectangular plug found on desktops, hubs and many older docks. Probably blue if USB 3.x to indicate “SuperSpeed”.
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USB‑B: Squarish and common on printers or older peripherals. Also found in enhanced USB 3.0 versions. Still compatible in shape but not always speed.
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USB‑C: A sleek, reversible oval connector. Modern, versatile, and capable of supporting USB 2.0 through USB4 protocols (and power delivery up to 240 W).
Protocol Versions: USB 2.0, USB 3.x, USB4
| Standard | Max Speed | Notes |
| USB 1.1 | 1.5–12 Mbps | Rarely used today |
| USB 2.0 | 480 Mbps | Basic standard, widely supported |
| USB 3.0 | 5 Gbps | SuperSpeed; backward compatible but limited by slowest link |
| USB 3.1/3.2 | 10 Gbps (Gen 2), 20 Gbps (Gen 2×2) | Rebranding of 3.x specs |
| USB4 | up to 40 Gbps | Dynamically manages video/data channels; |
Important: Even if you have a USB‑C port, you won’t automatically get USB4 speeds—it depends on the actual supported standard and cables in your chain.
How Form and Protocol Interact
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USB‑A and USB‑B can carry any supported protocol version—e.g. you might plug a USB‑A 3.0 drive into a USB‑A 2.0 port. It’ll work, but only at lower speed.
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USB‑C builds on modern protocols, but its presence doesn’t guarantee USB4 or high‑power delivery—it depends on device and cable specs.
Why It Matters—Scenario: A KVM Switch Setup
Imagine two laptops or PCs sharing the same dual‑monitor, keyboard, and mouse setup. A KVM switch (Keyboard‑Video‑Mouse) lets you toggle control between systems seamlessly.
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A modern USB‑C KVM can use MST (Multi‑Stream Transport) and EDID emulation to manage dual 4K@60Hz screens without glitch.
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It can also carry data, power, and network via a single USB‑C cable—ideal for docking scenarios.
Introducing TESmart’s KVM Models
TESmart CKS202‑P23
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Designed for 2 laptops + 2 monitors, with dual-monitor USB‑C input.
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Supports 4K@60Hz, MST, and EDID emulation for glitch‑free switching.
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Includes 36 W power delivery, 100 Mbps Ethernet, remote control, plug‑and‑play cable kit and built‑in docking features.
TESmart HDC202‑P23
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Built for 1 desktop + 1 laptop, also with USB‑C + HDMI/DP input, dual 4K60Hz output, MST, EDID, and docking support.
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Functions as a 9‑in‑1 hybrid docking station device—ideal for dual‑system users sharing peripherals and monitors using USB‑C connectivity.
Linking USB Knowledge to KVM Use Cases
Understanding the connector and protocol differences lets you choose correctly:
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Even if the KVM has USB‑C ports, if the devices only support USB 2.0 speeds, you won’t see USB4 performance.
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To achieve 4K60 high-resolution dual displays, your devices, cable, and KVM must support USB‑C with MST (i.e. at least USB 3.1/3.2) or better.
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Older USB‑A/USB‑B KVMs cannot match the features available via USB‑C chains.
Conclusion
USB types (A, B, C) define physical connection; USB standards (2.0, 3.x, 4) determine performance and capabilities. Mismatching them results in slower speeds or limited features. When using modern KVM switches like TESmart’s CKS202‑P23 or HDC202‑P23, understanding USB protocol support in your devices, cables, and switch matters—it's the foundation for seamless dual‑system, dual‑4K@60Hz workflow.
Now you’re ready to choose the right USB setup—and pair it with the right KVM—to power your multi‑pc workstation like a pro.
