26 terms

Glossary

The vocabulary that appears on accessory boxes, defined in plain language. Where a term has a full decoder page behind it, the link is under the definition.

Watt: A rate of energy transfer: volts multiplied by amps. On an accessory box a watt figure describes how fast energy can move, not how much of it is stored. A charger rated at 45W is describing a speed limit, and whether that limit is ever reached depends on what is plugged in.See alsoWatt-hour Port budget USB Power Delivery (PD)The wattage on the box is a budget, not a promise
Watt-hour: Energy: one watt sustained for one hour. This is the unit airlines and aviation regulators use for lithium batteries, because it accounts for voltage and milliamp-hours do not. Convert with mAh divided by 1000 multiplied by 3.7.See alsoMilliamp-hour (mAh)Watt Trickle mAh counts charge, watt-hours count energy
Milliamp-hour (mAh): A measure of charge, not energy. Without a voltage it cannot be compared across devices, which is why a phone battery in mAh and a power bank in mAh do not divide into a clean number of refills. Power banks are sold in mAh and regulated in watt-hours.See alsoWatt-hour Trickle Pass-through charging mAh counts charge, watt-hours count energy
USB Power Delivery (PD): A negotiation protocol published by the USB Implementers Forum. The charger advertises what it can supply, the device requests a combination it can use, and both agree before any real power flows. A listing naming PD is telling you more than a listing naming only a wattage.See alsoPPS (Programmable Power Supply)Quick Charge (QC)Watt Cable e-marker Power Delivery is a negotiation, not a speed
PPS (Programmable Power Supply): An extension of USB Power Delivery that allows fine voltage adjustment instead of a short menu of fixed steps. The practical benefit is less waste heat, because the charger tracks what the battery wants as it fills. Both the charger and the device have to support it.See alsoUSB Power Delivery (PD)Quick Charge (QC)GaN (gallium nitride)Power Delivery is a negotiation, not a speed
Quick Charge (QC): A fast charging protocol that predates the wide adoption of USB Power Delivery and usually appears on USB-A ports. It is not interchangeable with PD, and a block offering both is offering two separate systems on two separate ports.See alsoUSB Power Delivery (PD)PPS (Programmable Power Supply)Port budget Power Delivery is a negotiation, not a speed
GaN (gallium nitride): A semiconductor that switches more efficiently than silicon, producing less waste heat for the same output. It is why a high-wattage charger can be physically small. It does not make anything charge faster.See alsoWatt Trickle USB Power Delivery (PD)GaN is about size and heat, not extra speed
MagSafe: Apple's magnetic attachment and charging system for its own hardware, built around a defined ring of magnets in the phone. On a third-party listing, the phrase "MagSafe compatible" is a seller statement about magnet alignment rather than a certification by Apple.See alsoQi and Qi2 MFi Adhesive versus suction Magnets that stick are not the same as MagSafe
Qi and Qi2: The wireless charging standards published by the Wireless Power Consortium. Qi2 brought magnetic alignment into the open standard, which is why magnetic wireless charging is no longer exclusively an Apple arrangement. Alignment and charging speed remain separate questions.See alsoMagSafe Watt Milliamp-hour (mAh)Magnets that stick are not the same as MagSafe
MFi: Apple's accessory certification program, which covers Lightning connections among other things. An MFi claim in a listing is a statement about that program and not a statement about wattage, speed, or build quality.See alsoMagSafe USB-C alternate mode Cable e-marker The connector changed and the cable drawer did not
USB-C alternate mode: An arrangement where a USB-C port carries something other than USB data, most commonly a display signal. It is why two identical-looking USB-C ports on two devices can have completely different capabilities.See alsoCable e-marker USB Power Delivery (PD)MFi The connector changed and the cable drawer did not
Cable e-marker: A small chip inside a USB-C connector that tells the charger what the cable can handle. Without one, the chain drops to a conservative level regardless of how capable the charger and device are. This is the most common invisible bottleneck in a charging setup.See alsoUSB Power Delivery (PD)USB-C alternate mode Port budget The cable decides more of this than the charger does
IPX rating: The water half of the IEC ingress protection code. The X means the solid particle digit was not claimed, and each water level is a separate defined test rather than a point on a scale of general toughness. None of these tests cover salt water, soap, or pressure.See alsoTrue wireless Driver ANC (active noise cancellation)An IPX number is a lab test, not a swimming license
ANC (active noise cancellation): Microphones pick up outside sound and the earbuds play an inverted version of it. It works well against steady low-frequency noise like an aircraft cabin and poorly against speech. It is a listening feature, not hearing protection.See alsoTransparency mode Driver Codec Noise canceling, transparency, and what neither one is
Transparency mode: The same microphones as active noise cancellation, running the opposite way: outside sound is deliberately passed through so you can hear an announcement without removing anything. Some listings call it ambient or awareness mode.See alsoANC (active noise cancellation)True wireless Pairing Noise canceling, transparency, and what neither one is
Codec: The scheme used to compress audio for the wireless trip between the phone and the earbuds. Both ends have to support the same one, and when they do not, the connection falls back to a more basic option without announcing it.See alsoLatency Pairing ANC (active noise cancellation)Noise canceling, transparency, and what neither one is
Latency: The delay between a sound being sent by the phone and heard in the ear. It is invisible while listening to music and obvious while watching a video or playing a game, where it shows up as lips out of sync with speech.See alsoCodec Pairing True wireless Noise canceling, transparency, and what neither one is
Driver: The small speaker inside an earbud or headphone that actually moves air. A stated driver size describes the hardware, not the sound, and a larger number is not automatically better.See alsoANC (active noise cancellation)IPX rating True wireless Playtime hours usually count the case
True wireless: Two earbuds with no cable between them, paired with a charging case. The case is where the large playtime figures come from, since it recharges the buds several times over before it needs charging itself.See alsoPairing Latency Driver Playtime hours usually count the case
Pairing: The initial handshake that lets a phone and a wireless accessory recognize each other afterwards. On true wireless earbuds there are really two connections: phone to buds, and bud to bud, and the second one is usually what fails.See alsoTrue wireless Codec Latency Playtime hours usually count the case
Tether tab: A thin card that slides between a phone and its case, leaving a small loop poking out through the port opening for a strap to clip onto. It is what makes a phone strap compatible with a case rather than with a phone.See alsoKickstand Adhesive versus suction MagSafe
Kickstand: Any fold-out or rotating element that props a phone up on a surface. On grips it is usually a secondary position of the same mechanism rather than a separate part.See alsoTether tab Adhesive versus suction MagSafe
Adhesive versus suction: Two of the three ways an accessory attaches to a phone. Adhesive is effectively permanent and works on any phone; suction is temporary and depends on the surface, the temperature and how clean everything is. Suction should not be relied on over a hard floor, near water, or at height.See alsoMagSafe Kickstand Tether tab Magnets that stick are not the same as MagSafe
Pass-through charging: A power bank that can charge a device while it is itself charging from the wall. It turns the bank into a wall charger that keeps working when unplugged, and it generally runs warmer than either mode does alone.See alsoMilliamp-hour (mAh)Port budget Trickle mAh counts charge, watt-hours count energy
Port budget: The term this site uses for a wattage figure that covers an entire charger rather than any single port. Sixty watts across five ports is a budget of sixty watts, divided by rules the manufacturer usually does not publish.See alsoWatt Quick Charge (QC)Cable e-marker The wattage on the box is a budget, not a promise
Trickle: The slow final stage of a charge, where the rate drops sharply as the battery approaches full. It is the reason the last ten percent takes longer than the first fifty, and it is deliberate battery management rather than a fault.See alsoWatt-hour GaN (gallium nitride)Milliamp-hour (mAh)GaN is about size and heat, not extra speed