Take this test, and see how many tech specs you really understand

 18 Apr 2016 - 15:41

Take this test, and see how many tech specs you really understand
Rechargeable batteries have their storage capacity prominently displayed in milliampere-hours (mAh). The higher the number, the longer they keep working. (Andrea Warnecke / dpa)


The technology world is growing bigger and faster and it’s not always easy to keep up if you’re not a specialist. Even the specifications can be hard to follow when it's not clear what the units mean.

Here is a breakdown of some of the more important terms met in online shops. Take a test, and see how many units you already know.

Screen resolution: Pixels are the indicator for how sharp the screen resolution is. The more pixels - or dots - the sharper the images will be. The standard screen resolution of full HD movies is 1920 x 1080.

The ppi - or pixels per inch - is calculated by dividing the pixel resolution of a display by its physical size in one of the dimensions. So a full HD image will look a lot sharper when displayed on a laptop than on a cinema screen, where it would seem grainy.

Image resolution: The resolution for digital cameras is measured in megapixels (MP). One MP is 1 million regular pixels.

But since camera manufacturers calculate pixels differently than screen makers, megapixels and screen pixels are not comparable. A high number of MPs does even not necessarily mean high photo quality.

Too many MPs on a small sensor surface can lead to fuzziness known as image noise.

Brightness: This is important when buying projectors and is usually indicated in ANSI lumens with lower four-digit figures being common. Brightness in monitors, smartphones and tablets however is measured in candela (cd) per square metre and usually is in the middle three-figure digits.  

Electricity: There has always been plenty of potential confusion when talking about electricity, with measurements in amperes, volts and watts. Watts, in turn, relate to kilowatt hours (kWh), meaning a device rated at 3,000 watts needs three kWh of energy for one hour of activity.

Rechargeable battery storage capacity is indicated in milliampere-hours (mAh). The higher this value, the longer the battery will last with a full charge.

Storage units: Data size is measured in bits and bytes with 1 byte equalling 8 bits. One kilobyte is 1,024 bytes and 1,024 kilobytes equals one megabyte and so on. If you want to get advanced, define a petabyte (it's 1,000 terabytes) or a yottabyte (1 billion petabytes).

There's a caveat too. Device descriptions do not always indicate the data storage you will actually have available, since a small portion of physical storage is always kept back in reserve.

Data transfer rate: It’s important here to look closely at the figures. Surfing speeds are usually given in megabits or kilobits per second, but a data transfer rate - such as at a USB port - is measured in megabytes per second.

Therefore a USB 2.0 port with its 40 MB/s rate is much faster than a VDSL internet connection with 50 Mbit/s.

Speed: Hertz - measured in megahertz (MHz) or gigahertz (GHz) - is a unit of frequency and also for the speed of a processor.

The value specifies how many operations a processor can perform in a certain amount of time.

A higher hertz figure tends to mean more electricity needed and more heat within the computer. Most modern computers and smartphones use multiple processor cores to limit the number of GHz used.

Frame rate: The unit hertz is also used in moving images, indicating how many frames are displayed per second. The higher the value, the less shaky the images will seem to be. The long-time standard for televisions was 50 hertz, but now those values have jumped to 100, 200 and even higher.

PC monitors go up to 144 hertz. Frame rates for games however are stated in frames per second (fps) and not in hertz. Go figure. The minimum is considered 30 fps with 60 fps being the ideal value.

Diagonal: When buying a television you are not usually told the pixel proportions as with a computer monitor, but the display diagonal.

That is odd, but it has its uses. Experts say the ideal viewing distance to sit from a TV is two to three times the television’s diagonal. TV diagonals are usually given in inches even in nations that have never used imperial measurements.

One inch equals 2.54 centimetres, so sit about 100 inches (2.54 metres) from a 40-inch screen to enjoy it best.