(Pocket-lint) - The Apple Watch was announced late last year, but tonight's "Spring forward" event finally answered a few of the open questions we still had - specifically those centred on price and release date.

Before the event there were plenty of rumours on how much the different models would cost, especially the top-end devices, and whether it would come out in April or March. Now we know, so here are some of the things you need to know.

READ: Apple Watch will cost from £299 to a staggering £13,500, available from 24 April

The Apple Watch will be available in multiple territories, including the UK and US, from 24 April. Apple will be offering the opportunity to pre-order the watch from 10 April on Apple.com.

Prices for the Apple Watch dramatically vary depending on what model and what wrist strap you choose. Prices start at £299 for the 38mm Apple Watch Sport, £339 for the larger, 42mm model.

The stainless steel Apple Watch will range from £479 to £949. And the Apple Watch Edition, in 18ct gold, will start at £8,000 with the most expensive version - a 38mm model - at £13,500. In the US that's $17,000.

The stand-out feature on the Apple Watch is its Digital Crown, the dial on the side. It looks like the dial on a classic watch but has been added to enhance digital functionality rather than just to maintain classic timepiece aesthetics. The crown can be twisted to zoom in and out of maps or images or to scroll up and down web pages or text, meaning it should make navigation easy without the need to keep touching the screen.

There is no keyboard at all on the device, and all forms of input are handled with pre-populated options and voice dictation, through Siri.

The Digital Crown also acts as a home button when pressed in, and there is also a side button that can be used to quickly access contacts or a communications hub. The Watch itself is square rather than round, which came as a surprise to many people, and it will be available in the following sizes: 38mm and 42mm in height, which can be worn on either the right or left wrist.

The screen features a flexible Retina display, meaning it is sensitive to pressure allowing for more interactions from simple touch, and the glass will be either a single crystal of sapphire or Ion-X glass. The Watch will also come in a variety of materials and colours, including: Stainless Steel, Silver Aluminium, 18-Karat Yellow Gold, Space Black Stainless Steel, Space Grey Aluminium, and 18-Karat Rose Gold.

That's just the Watch itself. There are plenty of bands to mix that up even further, which should mean a nice variation, with the cheapest likely becoming the most popular. Band styles include the following: Link Bracelet, Sports Band, Leather Loop, Classic Buckle, Modern Buckle and Milanese Loop - a few of which use magnets to seal. Apple has revealed the Watch will come with 11 different faces.

There will likely be thousands of watch faces from third parties once the Apple Watch actually arrives.

Apple wants its Watch to become the centre of its our lives, controlling the smart home as well as tracking their health, so it needs to have plenty of sensors and communication capabilities built-in. For the first time, for instance, Apple has begun to introduce NFC in its mobile devices, including the Watch. Such functionality will allow owners of the Watch to tap-to-pay using their connected bank card via their iTunes account.

While the iPhone 6 and iPhone 6 Plus has the TouchID fingerprint reader for added security, the Watch does not (whether that means it will be limited to a £20 maximum per payment, while the iPhone may not, like current cards, isn't clear). It can also be used to access rooms in W Hotels. NFC in the Watch could also be used, presumably, to pair with devices like speakers and possibly even ride the Underground like using an Oyster.

Heart rate sensors are also built into the Watch with four optical sensors encased in scratch resistant sapphire glass. Using light, these are able to detect and measure the wearer's heart rate (how accurate this is hasn't been made clear until we test it ourselves).

And finally, there's no GPS, but tracking can be done using the accelerometer.

Apple revealed during the launch event that the Watch App Store will be accessible through the iPhone with dedicated Watch apps being sideloaded onto the wrist-worn device.

In addition, iPhone apps will automatically forward notifications to the watch, so things like WhatsApp will notify you on the Watch as that shows the same notifications that would appear on the phone.

It will have a full Notification Center like the iPhone, iPad, and Mac. To access Notification Center, you'll swipe down from the top of the display in any screen, and the list of notifications will show each app name with descriptions of the alerts. Developers will be able to customise their notifications in the Notification Center as well as the Apple Watch app icon in this view.

Apps will have varying levels of interaction on the watch. Glance will display a snippet of information by swiping up, with more by then swiping left and right (a bit like Cards on Android Wear). But it goes deeper with Short Look and Long Look: a notification will display, but if you keep your wrist up, that will change to include more information like an imminent flight time then details about that flight.

You will also be able to make and receive phone calls from the Watch, which is cool.

The face of the watch is customisable and we expect a whole swathe of different options to be available. Most of the faces offers some at a glance information, including Timelapse, Astronomy, Solar, Moon, Events, and Activity level displays.

Smart Replies is a potentially helpful offering. It reads your messages and offers intelligent reply options based on the content. So, if your mate asks what time you want to go to the cinema out of 7:30 and 8:15, the watch will, theoretically, have response options like "7:30 is great" or "8:15 works for me" or "I can’t make any of those", for instance. You can also dictate a response, if you so desire.

Handoff is another feature the Watch will utilise. This will allow you to begin reading a message on one device and continue on another. It was introduced in iOS 8 and OS X Yosemite so will work across any device with those operating systems installed. Watch will also work with HomeKit and HealthKit, meaning it can be used to control the home with things like heating, automated garage doors, etc - all commanded from the wrist.

Glance is one more feature that's exciting. It allows you to see information at a lift of the watch itself. The face will light up after detecting the movement and display information like location, events, news, and more. And finally, Digital Touch is a fun extra feature that Apple has added. It allows Watch you to doodle on your device and send that image to another Watch owner. It's a bit like emoticons but personalised.

Apple has designed two modes of the Watch, allowing it to be used both for sports and fitness tracking.

Activity is the always-on tracker, which uses the Watch's barometer and accelerometer to track the wearer's daily step count, and when combined with height, age, and weight information, it should be able to accurately measure calories burned.

Fitness is the sports mode for the watch. It can track a run, cycle or workout. It uses the built-in sensors, allowing heart rate to be displayed and used to define a workout, and when combined with the iPhone, it will be able to map routes for accurate distance or for planning runs.

Storage



According to Apple, Apple Watch will be able to store music and photos (even while unlinked to an iPhone). The device will include 8GB of storage, for instance, and you will be able to specify individual songs, albums, and playlists to be loaded to onto your Apple Watches via the Companion app for iPhone. You will even be able to stream music from the Apple Watch to external speakers or headphones via Bluetooth.

Force touch

Force Touch was announced at the original Apple Watch event. It gives the device the ability to recognise the difference between a normal touch and a press, so the depth of controls from a single finger touch can increase meaning even less tapping and swiping, theoretically. Apple has called Force Touch its "most significant new sensing capability since Multi-Touch".

S1

Apple Watch features Apple's custom S1 system-in-a-package chip, and it is reportedly comparable with the current iPod touch’s A5 chip. It should be able to handle several apps, though reports have claimed an Apple Watch with over 200 WatchKit app will run sluggish.

The Apple Watch doesn’t need any cables plugged directly into the device, thanks to a magnetic inductive charger. It attaches to the rear of the watch and delivers power over the cable from the wall socket. It uses MagSafe technology, similar to what's used in Apple's MacBook laptops.

Apple claims that the watch will have an 18-hour battery life, but that will become apparent in full tests.

It might be because the Apple Watch will also have a battery-preserving “Power Reserve” mode, in which the device shows only the time. The mode will not only cut functionality to just the time but also dim the display, slow down communication with the iPhone, and put the display to sleep after two seconds of inactivity.

And finally, to turn off the Apple Watch, you'll have to long press the large “communication button” on the right side of the Watch. That'll display a confirmation slider just like the one on the iPhone and iPad. You will also be able to do a Force Quit on an unstable app by accessing the shut down screen and then quickly pressing the button on the right side.

READ: Apple Watch preview: Apple hopes it's time for the ultimate iPhone accessory

Writing by Luke Edwards and Elyse Betters.