Microsoft launched its highly-anticipated Windows Phone 8.1 update at its keynote address at the Build 2014 conference on Wednesday. The event also saw the unveiling of the Windows 8.1 Update operating system version, alongside three new devices, Nokia Lumia 930, Lumia 630 and Lumia 635, which will be the platform lead devices for Windows Phone 8.1 OS version.
Microsoft's Joe Belfiore, VP Windows Phone program management and design, introduced a bevy of enhanced features in the Windows Phone 8.1 that the Redmond giant hopes will bring more personal and smarter experience for consumers.
Microsoft has announced that Windows Phone 8.1 will start rolling out to Windows Phone 8 users in coming months. The Redmond giant also confirmed that the entire Nokia Lumia range will get OTA (over-the-air) update called Lumia Cyan, which will include Windows Phone 8.1 features and the new Lumia features into one update.
We've broken down the eight biggest new features in the Windows Phone 8.1 including the ones that made it into the highlights - Cortana, Action Centre, Word Flow and more personalised Start Screen.

1. Greater Start Screen personalisation
Microsoft in an attempt to offer more customisable options to Windows Phone users, has added 'Start background' feature that allows users to add an image to the tiles on the Start screen of the device.
new_start_screen_personalisation_microsoft.jpgThe feature will add an image of the user's choice to multiple tiles on the Start screen. Earlier, the Live Tiles on the Start screen on Windows Phone 8 were limited to solid colours.
In 2013, Microsoft added the third Live Tile column on the Start screen of the Nokia Lumia 1520, and then left it to manufacturer adoption. However, with the Windows Phone 8.1, the company has now added an extra column of Live Tiles on all screen sizes, with users able to choose whether to turn this feature on.

2. Cortana: Finally arrives to take on Apple's Siri and Google's Google Now
One of the highlight features of Windows Phone 8.1 is Cortana, which is Microsoft's voice-based virtual assistant. The Redmond giant's Cortana is based on a popular AI character in Microsoft's blockbuster video game franchise, Halo.
Cortana is powered by Bing and is similar to Apple's Siri or Google Now, completely replacing the search feature in WP8.1. Microsoft's Joe Belfiore claimed that the new digital assistant from Microsoft will get better with time as a user spends more time with it by asking questions to Cortana, filling up details in its Notebook section.
windows_phone_8_1_cortana_screenshot.jpgCortana can be launched by pressing the Live Tile placed on the Start screen or by pressing the Search button on the Windows Phone device. Belfiore said that Cortana can interact verbally or by typing, and stressed its ability to understand natural language voice commands. It can also interact with third party apps, though developers will have to build Cortana-compatibility into their apps.
Microsoft has announced that Cortana will be available first in the US as a 'beta' and later will released in the UK and China in the second half of 2014, while in other countries Cortana might reach by 2015.
windows_phone_8_1_action_centre.jpg
3. Action Centre for notifications
Microsoft has finally launched one of the most awaited features on Windows Phone platform, the Action Centre. The Windows Phone 8.1 update brings the Action Centre to all Windows Phone-based devices which will show notifications for calls, messages, emails, apps and others. It will also offer quick settings access to Flight Mode, Bluetooth, Wi-Fi, and Rotation Lock options. Notably, the quick access options are customisable.
The Action Centre for Windows Phone 8.1 can be accessed by a simple drop down swipe gesture like seen in Android and iOS.

4. Word Flow Keyboard
Another big addition in the Windows Phone 8.1 has been the introduction of the Word Flow Keyboard, which is a Swype keyboard-like feature for Windows Phone users. The Word Flow Keyboard allows users to glide over the display and type words.
Microsoft claims that the Word Flow Keyboard is one of the 'most intuitive smartphone keyboards' and learns from users writing style. Belfiore noted that the Word Flow Keyboard supports 16 languages, though has not named the languages supported.
Belfiore even claimed that, thanks to Word Flow Keyboard, a kid was able break the Guinness World Record for fastest writing on a smartphone earlier held by Swype keyboard on a Samsung Galaxy S4.
skype_dialler_integration_windows_phone_8_1.jpg
5. Skype Integration
Microsoft has also upgraded the Skype integration in Windows Phone devices with its latest Windows Phone 8.1. Now, the new Skype app for Windows Phone 8.1 comes with dialler integration that allows a user to switch a regular call to a Skype video call with a click of a button. Further, Skype has also been designed to work with Cortana, as users can setup Skype calls via the new voice-based virtual assistant.

6. Upgraded imaging experience
Microsoft takes the Windows Phone photography experience to the next level with the revamped Camera Roll, which gives quick access to clicked images, image tweaking tools and sharing capabilities.
The Smart Shots, Cinemagraphs, and Refocus photos options are directly accessible now from Camera Roll. Microsoft has also added the burst mode features to its Windows Phone 8.1 for clicking continuous images.
Creative Studio has been also added to the Camera Roll, which can use five new filters. The Nokia Storyteller has also received a slight addition with new video slideshow option that allows sharing via Facebook and Twitter.

7. New Sense feature for Windows Phone users
Microsoft has introduced the new Sense apps that include Data Sense, Wi-Fi Sense and Storage Sense.
sense_apps_windows_phone_8_1.jpgData Sense gives a detailed track of data usage on a Windows Phone, which could be braked down according to time- a month, a week etc. Data Sense includes a 'high savings' mode that the company claims will compress the images browsed on the Web, so a user can search more without with less data usage.
Another Sense app is Wi-Fi Sense, which automatically connects to a nearby Wi-Fi hotspot (when detected) to conserve cellular data.
Notably, when Wi-Fi is turned off in Wi-Fi Sense; Cortana can automatically turn it on, when a favourite location with hotspot is available.
Storage Sense can help users manage content stored on the microSD card and inbuilt storage by moving apps, music, images and videos between inbuilt storage and microSD card.
In addition, Microsoft has also improved its Battery Sense feature, giving a breakdown of apps' battery consumption, and also includes an 'automatic mode' in the Battery Saver option that can help extend battery life.

8. Slew of new delights
Apart from the major highlights of the Windows Phone 8.1, Microsoft has also added a number of minor tweaks to its OS.
nokia_lumia_630_lumia_635.jpgAfter multiple leaks, the onscreen keys are official with Windows Phone 8.1. The onscreen keys for Search, Start and Back will now appear at the bottom of the display and this will mean that future Windows Phone 8.1-based devices will not feature the three capacitive buttons at the bottom of the front panel.
new_lockscreen_windows_phone8_1.jpgMicrosoft has also introduced the new Lock Screen, which now comes with multiple Lock Screen themes featuring different visuals and animations - APIs are also available for developers to create their own themes and widgets.
The Calendar app has received a redesign and now shows a week view, along with a weather widget which has been integrated into the Calendar app. It will show at the top.
Various apps such as Music, Video and Podcasts have received improvements and are now split apps, all capable of update vie the Store.
The Internet Explorer 11 for Windows Phone 8.1 was also introduced. The new IE11 comes with new features such as InPrivate browsing, password caching, and a super-handy reading mode.