Sat navs: Jargon buster

Bluetooth

Bluetooth lets your mobile connect to your sat nav

Bluetooth is a wireless technology that lets a sat nav communicate with a mobile phone. Some sat navs can be set up to act as hands-free kits - a legal alternative to using your handset at the wheel.

ETA

The estimated time of arrival, usually shown in hours and minutes on your sat nav, tells you how long it will take you to reach your destination under current driving conditions.

Heavy traffic, bad weather and wrong turns can all increase your journey time.

GPS

Sat nav systems detect where your car is using global positioning system (GPS) technology.

Satellites orbit around the Earth and communicate with each other – and your sat nav – to provide your location.

HD Traffic

This is TomTom’s name for its traffic information service. It is sophisticated, drawing on data from several sources to map real-time traffic hotspots and then calculate a route round them.

Most sat navs can find the nearest petrol station; some even show live fuel prices

Points of Interest

These are locations on your map that may be of interest – petrol stations, railway stations, restaurants and hospitals are some of the most common ones. Many are pre-installed on your sat nav, but you can add more if you wish, from supermarkets to DIY stores. Over time, you can update them when you update your maps. 

Mobile phone sat nav apps also display contact information for the point of interest and enable you to call it on your phone.

Smartphone

A smartphone is a high-end mobile phone. Many of them feature GPS technology. Download as app and it can be used as a sat nav.

This TomTom model is showing roadworks en route, and estimated delays in minutes

Traffic information

Traffic information is used by your sat nav to help you avoid jams and troublespots.

Some sat nav makers offer traffic information for free, but with most systems it is an optional extra, paid for via a one-off fee, or a monthly or annual subscription.