Port and Connector Types for CompTIA A+ 220-1101

USB-A: rectangular, standard host port on PCs. USB-B: square with beveled top corners — printers, older scanners. USB Mini-B: trapezoidal, 5-pin — older cameras, MP3 players (mostly obsolete). USB Micro-B: smaller, 5-pin, asymmetric — Android phones pre-USB-C, external hard drives. USB-C: oval, reversible, 24-pin — modern standard for phones, laptops, peripherals. USB 3.0 (USB 3.1 Gen 1 / USB 3.2 Gen 1): 5 Gbps, blue color-coding on Type-A ports. USB 3.1 Gen 2 (USB 3.2 Gen 2): 10 Gbps. USB 3.2 Gen 2x2: 20 Gbps (USB-C only). USB4: 40 Gbps (USB-C connector, Thunderbolt 3 compatible). USB 2.0: 480 Mbps (black or white ports). USB 1.1: 12 Mbps (largely obsolete). Identifying tip: blue USB-A port = USB 3.0; yellow USB-A = always-on charging.

Thunderbolt 3 and 4: use USB-C connector. Lightning bolt icon distinguishes from standard USB-C. Thunderbolt 3: 40 Gbps, supports DisplayPort 1.2, PCIe x4, can charge laptops, daisy-chain up to 6 devices. Thunderbolt 4: 40 Gbps, stricter spec than TB3 — requires 2 video outputs, 32 GB/s PCIe minimum. Thunderbolt 1 and 2: use Mini DisplayPort connector (not USB-C). Thunderbolt 1: 10 Gbps. Thunderbolt 2: 20 Gbps. Thunderbolt is Intel-developed technology, now part of USB4 spec. Thunderbolt devices backward-compatible with USB-C ports (at USB speeds, not Thunderbolt speeds). USB4 devices backward-compatible with Thunderbolt 3 ports.

3.5 mm TRS (Tip-Ring-Sleeve): the standard analog audio jack. Colors on PC: green = front speaker out/headphones, blue = line in, pink = microphone. 3.5 mm TRRS (4 pole): includes microphone on same jack — used on smartphones and headsets with combined audio/mic jack. 6.35 mm (1/4 inch): professional audio, guitar amplifiers. RCA: red (right audio) + white (left audio) + yellow (composite video) — consumer audio/video equipment. XLR: 3-pin professional audio connector for balanced audio — microphones, mixing boards. S/PDIF: digital audio. Optical (TOSLINK): fiber optic cable with square connector. Coaxial S/PDIF: RCA-like connector for digital audio. HDMI carries digital audio alongside video — replacing separate audio connectors in modern setups.

DB-9 (DE-9) / RS-232 serial: 9-pin D-sub connector — used for legacy serial devices, networking console ports, UPS management ports. DB-25: 25-pin D-sub — legacy parallel port (printers) and serial port variant. Parallel (LPT) port: 25-pin female D-sub on PC — used for older printers (Centronics Parallel). PS/2: round, 6-pin Mini-DIN — purple = keyboard, green = mouse. Cannot be hot-swapped (must plug in before powering on). DIN-5: 5-pin round connector — legacy keyboard. Game port: 15-pin D-sub — legacy joystick/gamepad connector. These connectors are obsolete in modern PCs but appear in A+ questions about legacy system support and upgrade paths.

RJ-45: 8-pin, 8-position modular connector — Ethernet networking. Wider than RJ-11. RJ-11: 6-position (4-pin used) — telephone, DSL modem. Narrower than RJ-45. F-connector (coaxial): threaded, used for cable TV, cable modem, satellite. BNC: bayonet-mount coaxial — older 10Base2 Ethernet (Thinnet), video surveillance. LC fiber: small form factor (SFF), push-pull latch — most common in enterprise SFP modules. SC fiber: square, push-pull — older enterprise and telco. ST fiber: bayonet-mount, round — older multimode fiber installations. MTRJ: small, duplex fiber connector — less common. SFP/SFP+ slots: hot-swappable transceiver slots on switches — accept LC fiber or copper (RJ-45) SFP modules.

SATA data cable: 7-pin, thin L-shaped, used for all SATA drives. SATA power: 15-pin, wider L-shaped connector from PSU. Molex: 4-pin, legacy power connector — older IDE drives, fans, case lighting. IDE/PATA: 40-pin ribbon cable — legacy parallel ATA hard drives and optical drives. PCIe slots: x1 (short), x4, x8, x16 (longest — graphics cards). M.2 slot: small rectangular slot on motherboard for M.2 SSDs and Wi-Fi cards. M.2 key types: M-key (PCIe NVMe), B-key (SATA), B+M-key (compatible with both). U.2: enterprise 2.5-inch NVMe drive connector (enterprise). External: eSATA (external SATA), USB (most common for external storage), Thunderbolt.