Windows 7 is a version of Windows that succeeded Windows Vista. Compared to its predecessor it provides high speeds and streamlines the interface while maintaining valuable features such as the User Account Control sandbox and the Aero graphical enhancements. In many respects it is very moderate sitting at the centre of a web of operating systems with many different traits.
Some Good Some New Some Old
The biggest changes to Windows 7 aren't as obvious as booting up to the desktop (though the background and default colours differ from Vista!). 7 reordered major interface elements and applets from the Control Panel and beyond. Enough elements more (such as the Start Menu) closely resemble its predecessors though that it's still fairly familiar for anyone moving to it and overall its changes are positive and efficient. It also runs very smoothly compared to XP and Vista and its taskbar and other elements use very slightly less screen real estate.
A Good OS Stands the Test of Time
Overall Windows 7 is a great choice of operating system for just about anyone. It is a rock solid operating system with few flaws save that support for it will end sooner than other operating system options. If you are willing to learn how to navigate the 7's Control Panel and get used to a few other unique traits it has Windows 7 is an all-around fantastic choice.