Apple’s iBeacon is suddenly in the news a lot, and will soon show up at major sporting events, big retail stores and elsewhere.

The beacon revolution is being presented as an Apple thing for Apple users. But as with so many technologies, Apple didn’t invent beacons. It was here before Apple’s version got here. And it’s not just for Apple users — even Apple’s iBeacon supports Android.

Here’s everything you need to know about beacons.

What is a beacon?

We’re entering the Age of Context. That means (among other things) that information will be presented to you based on your situation, circumstances and individual needs and preferences.

One of the most important contextual data points is location. Where are you? Rather than reminding you to buy a loaf of bread when you’re getting in bed, it will remind you as you walk into the store.

For the past few years, smartphone location has been determined by one or more ways. GPS, which finds your location by satellite. Cell tower triangulation does something similar but with cell towers instead of satellites. And connecting to WiFi also pinpoints your location when the system knows where the WiFi hotspot is. These are typically combined to find location on your smartphone.

GPS doesn’t work indoors. And the range can be very general. Sometimes regular methods of location can find you to within a few feet, but other times only within a quarter mile. (Or it can’t find you at all.)

Beacon technology is simply a way to use Bluetooth to pinpoint a device’s location, even indoors and with more precision.

A beacon is just a Bluetooth low energy proximity sensor. It’s main job is to enable a uniquely identified device (usually a specific smartphone running a beacon-enabled app) to know it’s position to within a few feet.

Specifically, Bluetooth 4.0 (also called Bluetooth Smart and Bluetooth Low Energy or BLE) makes beacons practical. The low-energy aspect of BLE will mean that beacons can be created for about $10 and run for two years on a AA battery.

What is iBeacon?

Apple’s iBeacon is nothing more than Apple’s own version of the beacon concept, and it’s currently built into iOS 7. That means every iOS 7 device can function as both a beacon and also a “client,” if you will, of the iBeacon system.

iBeacon both identifies the location of a phone or tablet, but also can trigger an action, such as launching an app or doing a check-in.

Is iBeacon just for Apple users?

Surprisingly, Apple’s iBeacon supports Android devices. If a store, stadium or home automation product goes with iBeacon, and uses Apple’s iBeacon API, Android users can still take advantages of it if an Android app has been created for it.

What are the non-Apple alternatives?

Other major beacon companies include Estimote, Gelo (pronounced JEE-low), Swirl, Beaconic and perhaps the newest and most interesting company, Datzing.

Datzing is interesting because it’s an Android (for now). It’s currently in beta, but is expected in the Google Play Store by summer.

The free app turns your Android phone into a beacon (the first beacon is free and they charge for each additional beacon you set up). Interestingly, it uses both WiFi and Bluetooth. You’ll be able to set up information that you can broadcast and share whatever information you want. They call it a “wireless QR code” — the idea being that you can push information to devices within range without scanning anything.

While Apple’s iBeacon lets you use any Apple device as a beacon, Datzing will let you use any device that supports either WiFi or Bluetooth as a beacon.

Why should I care about beacons?

Indoor location and beacons are quickly becoming ubiquitous. As application makers increasingly build beacon support into their apps, you’ll almost certainly use it every day, all day both for the standard reasons — retail, check-ins, indoor navigation, transactions — but also reasons nobody’s thought of yet.

The most important thing to know about beacon technology is that it’s here. It’s not an Apple thing. And it’s going to change the way we all live our lives.