Tech reviews are full of jargon that's rarely explained. This glossary translates the specs that actually affect what you buy — in plain language, with the honest context of when each one matters and when it's just a number on a box. Bookmark it and check back whenever a review throws a term at you.
ANC (Active Noise Cancellation)
Microphones on the headphone listen to outside sound and generate an opposite sound wave to cancel it. It works best on constant low drones — plane engines, train rumble, AC hum — and far less on sudden noises like voices. More ANC isn't always better; comfort and how it handles wind matter just as much.
Transparency / Ambient mode
The opposite of ANC — the headphone pipes outside sound in so you can hear your surroundings without taking the buds out. Useful for crossing a road, ordering coffee, or hearing a gate announcement.
OLED
A display where each pixel makes its own light, so black pixels are switched fully off. That gives perfect blacks, vivid color and great contrast. The trade-off is potential for burn-in over years of static images, and usually a higher price than LCD.
LCD / IPS
The older, cheaper display type that uses a backlight shining through liquid-crystal pixels. Blacks look more grey than OLED because the backlight never fully switches off, but LCDs are bright, reliable and cost less.
Mini-LED
An LCD upgrade that splits the backlight into thousands of tiny zones that dim independently, getting closer to OLED's deep blacks while staying very bright. Common on premium tablets and laptops.
Refresh rate (Hz)
How many times per second the screen redraws. 60Hz is standard; 120Hz makes scrolling and animation look noticeably smoother. Higher refresh costs battery, which is why many phones vary it automatically.
ProMotion / Adaptive refresh
A marketing name (Apple's is ProMotion) for a screen that changes its refresh rate on the fly — dropping to save power on a static page, jumping to 120Hz when you scroll or game.
Nits (brightness)
A measure of screen brightness. Higher nits mean a screen you can actually read in direct sunlight. Around 1,000 nits is good for a phone outdoors; 2,000+ is excellent.
HDR (High Dynamic Range)
Lets a screen show brighter highlights and more shades between dark and light at the same time, so a sunset or a flashlight in a dark scene looks more lifelike. Needs both HDR content and an HDR-capable screen to matter.
Codec (LDAC, aptX, AAC, SBC)
The format Bluetooth uses to compress audio between your phone and headphones. LDAC and aptX (Android) carry more detail than the basic SBC; AAC is what iPhones use. The catch: both devices must support the same codec, or it falls back to the lowest one they share.
Spatial audio
Processing that makes sound seem to come from around you rather than inside your head, often tracking your head movement so the 'stage' stays put when you turn. Great for film; a matter of taste for music.
Driver (in headphones)
The tiny speaker inside each earcup or earbud that actually produces sound. Size and type affect the character of the audio, but a bigger driver doesn't automatically mean better sound — tuning matters more.
Mirrorless camera
A camera with no internal mirror, so it shows you a live digital preview through the viewfinder. Lighter and quieter than the DSLRs they replaced, with better video and autofocus. This is the standard for new cameras today.
DSLR
The older camera design with a mirror that flips up to take the shot, giving an optical (not digital) viewfinder. Largely superseded by mirrorless, though plenty of great used DSLRs and lenses remain.
Full-frame vs APS-C
Sensor sizes. Full-frame is larger, gathering more light for better low-light performance and shallower background blur, but the bodies and lenses cost and weigh more. APS-C is smaller, lighter and cheaper, and excellent for most people.
IBIS (In-Body Image Stabilisation)
The sensor physically shifts to counteract hand-shake, letting you shoot sharper photos in low light and steadier handheld video. Hugely useful for travel and run-and-gun video.
Aperture (f-number)
How wide the lens opening is. A lower number (f/1.8) lets in more light and blurs the background more; a higher number (f/8) keeps more of the scene in focus. It's one of the three pillars of exposure alongside shutter speed and ISO.
Unified memory
On Apple silicon, the RAM and graphics share one fast pool of memory instead of separate chips. It's efficient, but it can't be upgraded later — so buy more than you think you need up front, especially the 16GB-versus-more decision.
NPU / TOPS
An NPU is a chip section built for AI tasks; TOPS (trillions of operations per second) is the marketing number for how fast it is. Relevant for on-device AI features, but for most buyers it's not yet a reason to choose one device over another.
Wi-Fi 7
The latest Wi-Fi standard, offering faster speeds and lower lag when you have a Wi-Fi 7 router to match. Nice future-proofing, but you won't notice it without the matching router and a fast internet connection.
Thunderbolt / USB4
The fastest USB-C connections, handling data, external displays and charging over one cable. Thunderbolt 5 and USB4 are great for docks and external drives. Not every USB-C port is this fast — check the spec, because they look identical.
IP rating (e.g. IP68)
A two-digit dust-and-water resistance score. The first digit is dust, the second water; higher is tougher. IP68 means dust-tight and able to survive submersion. It's protection against accidents, not an invitation to go swimming.
mAh (battery capacity)
A rough measure of how much charge a battery holds — bigger usually means longer life, but efficiency of the chip and screen matters just as much. A smaller battery in an efficient phone can outlast a bigger one in a power-hungry phone.
Fast charging (W / watts)
How quickly a device refills. Higher wattage means faster top-ups, but you often need the right charger and cable to hit the advertised speed — and the fastest chargers are frequently sold separately.
Qi2 / MagSafe
Magnetic wireless charging that snaps accessories and chargers into the right spot on the back of a phone. MagSafe is Apple's version; Qi2 is the open standard built on the same idea.
eSIM
A SIM built into the device that you activate digitally instead of inserting a plastic card. Handy for switching carriers or adding a travel plan instantly, though not every carrier worldwide supports it yet.
VRR (Variable Refresh Rate)
On a console or TV, the display syncs its refresh to the game's frame rate to eliminate screen tearing and stutter. Needs both the console and the TV to support it.
Ray tracing
A graphics technique that simulates how light actually bounces, for more realistic reflections and shadows in games. It looks great but is demanding, so it can lower frame rates unless the hardware is powerful enough.
SSD vs eMMC storage
SSDs are fast modern storage; eMMC is the slower, cheaper kind found in budget devices. On a handheld or laptop, SSD storage means quicker load times and a snappier feel — worth prioritising over a slightly bigger eMMC.
Color gamut (DCI-P3, sRGB)
The range of colors a screen can display. sRGB is the web standard; DCI-P3 is wider and used for film and photo work. A 'P3' screen shows richer, more accurate color for creative tasks.
Definitions written by SIGNAL. Suggest a term we missed via the Write a Review form.