Windows 10 Features

Productivity

Cortana/Search Box – A better search engine to Search your PC and the web from the taskbar to find help, apps, files, settings. 
Virtual Desktop - Virtual desktop allows you to move easily across desktops allowing you to organize and quickly access groups of Windows. 
Task View – Task view is also where you can go to switch between desktops. The top part of this view shows previews of the windows you have open, just like Alt+Tab 
Snap Assist - Snap Assist in Windows 10 helps you arrange your windows and apps effortlessly, with new, efficient ways to optimize your layout on tablets, large monitors or multi-monitor setups. 
File Explorer – Quick Access allow one to access recently accessed Folders and document on your Windows 10. 
Extending the display in Windows 10 - You can add multiple displays to your Windows 10 PC and extend the display, thereby improving Productivity.

Securing the OS and boot process at the hardware level. Windows 10 leverages UEFI (replacement for BIOS), TPM (Hardware based certificate store), Early loading of Anti-Malware, secure boot and measured boot, securing the Windows kernel from root kits and boot kits. 
Two factor authentication with “Passport” and biometric log-in with “Windows Hello.” 
Device Guard - a technology that requires applications to be “signed” and verified before they can be installed on a Windows 10 machine.   Not there in Pro 
“Virtual Secure Mode” – The Local Security Subsystem (LSS), Password hashes and identity information are contained in a small virtual machine that segregates identity from the Windows Kernel, to prevent pass-the-hash attacks.   Not there in Pro 
App Locker– A tool that enables administrators to “white list” and “black list” applications.  Not there in Pro 
Microsoft BitLocker Administration and Monitoring– Control and enforce BitLocker drive encryption policies.  Enable self-service for BitLocker enrollment and recovery. 
Identity Choice – Use existing Active Directory and take advantage of Azure AD for cloud based identity.  Enable self-service enrollment, Single sign-on, Multi-factor authentication.

Current Branch for Business – No large service releases.  Windows 10 will utilize a process of continuous improvement and deliver feature updates on a regular basis (every 4 months). 
Windows Update for Business – Enterprises can leverage “Windows Update for Business” to vet and approve feature updates, and create deployment “rings” to rollout Windows.  
Upgrade from previous versions – Moving to Windows 10 is an upgrade from Windows 7 and 8.  User settings and documents are preserved.  
Runtime Configuration – Moving to another Windows runtime (Pro to Enterprise, for example) is also an upgrade. No reimaging is required.

Platform Convergence – One Windows across devices, from the smallest IOT devices to the largest Surface Hub workspaces, the code base is the same 
Continuum – Windows 10 has the ability to “sense” screen size and input types (touch, keyboard, mouse, etc.) and adjust accordingly.

Will work with existing (Windows 7 and higher) hardware

A great user interface – The best of Windows 7 and Windows 8.  Start Menu, live tiles, optimized for mouse, keyboard, touch and voice. 
Cortana – An Intelligent personal digital assistant. 
Edge – The new browser that is super-fast and feature rich. 
The New Command Prompt – The New Command Prompt is integrated into File Explorer for easy access. In addition, you are able to copy/paste and drag/drop items into the new improved command prompt.

Join to Azure Active Directory – Window 10 allow support for domain join to Azure Active Directory. 
Enhanced Mobile Device Management – Windows 10 support for Group Policy and WMI, and it advances its MDM support in significant ways. With the Unified Windows Platform, for example, the MDM capabilities will be present and consistent on all Windows 10 devices and form factors.