Microsoft has a lofty vision for Windows 10 - one
operating system core for all devices called OneCore. One of the keys to making
that vision a reality for smartphones is a software feature called Continuum. With
Continuum for phones, Microsoft believes any phone can be your PC. Microsoft
aims to turn Windows 10 phones into full-blown PCs when they’re connected to
PCs. Also, with Windows 10 phones, the devices will perform similarly to a
traditional PC when they’re connected to an external monitor, along with a
Bluetooth mouse and keyboard.
Continuum is a software tool that will aid Windows
10 in detecting what type of device a user is on and help the operating system
configure itself accordingly. It is integral for Surface and other convertible tablets
that double as laptops. For instance, Continuum will be able to know when
you're using Windows 10 with a mouse and keyboard attachment and when you've
switched to a touch interface with finger- and pen-based inputs.
Microsoft’s universal apps use the same basic code
base across devices and scale to fit the screen they’re being used on.
Continuum is Microsoft's solution for shifting among various form factors.
When a Windows Phone is plugged into a PC monitor, a
PowerPoint app is treated like a PC app because it is in fact the same code
that one would see for PowerPoint on a PC. When numerous tablet apps are opened,
Continuum would switch them to PC-style apps when the device is docked. Even
desktop-centric stuff will work just fine. Seamless copying and pasting between
mobile-centric apps, and yes, even the legendary ALT-TAB are available now. Continuum for
Phones changes the interface on the screen it's connected to and gives you extra
tools on the handset as well. Microsoft calls it a "PC-like
experience".

Windows 10's Mail app running on a Windows Phone connected to an
external monitor, using Continuum.
When you first connect your phone to a keyboard and
screen using the new Connect button in the Action Center (which Microsoft also
refers to as 'docking'), a notification at the top of your phone screen asks if
you want to use the phone as a trackpad to control the cursor on the other
screen - that's an app that gives you an experience very like controlling an
Xbox with the SmartGlass app on your phone. (It helps to turn the phone
sideways, so it looks like a trackpad, and to put it down in front of the
keyboard). Or you can keep using the handset with the usual phone interface. Apps you
launch by touching the phone screen stay on the phone screen - so you could
project PowerPoint for a presentation but keep your email and personal text
messages off the big screen. There will be a gesture to move an app from the phone
screen to the big screen and back.
If what you're running is a web application from
the Windows Store, it will give you a different interface if it uses responsive
design. But if it's an Android app packaged for Windows 10 for Phones (or an
iOS app that the developer hasn't added extra features to), you'll just get the
standard phone app interface, only bigger.

Soon, one can rely solely on a smartphone for their
computing needs.
Microsoft
says that Windows 10 would launch late July in 190 countries and 111 languages.
Windows 10 is showcased as a simpler, more modern OS that seamlessly ties together
desktops, laptops and smartphones. Microsoft calls it not just another release
of Windows "but a new generation of Windows built for an era for more
personal computing, from Raspberry Pi to the holographic computer, where the
mobility of the experience is what matters, not the mobility of the
device."