The three main areas that Apple has improved in OS X Yosemite is the interface, app enhancement and a new piece of software called 'Continuity'.
As rumours originally suggested the user interface has received a similar facelift to that of iOS 7. Apple has redesigned the application icons and the dock to make them appear ‘flatter’; also windows now have an area of transparency so that app interfaces just fade away.
Apple has also implemented a new 'dark mode' for users who work in areas with lower light. The new feature will help reduce eyestrain that users might experience with a bright user interface.
Yosemite's new 'Notification centre' also adopts some of the features of iOS. It has gained a 'Today view' so you can see forthcoming calendar events. In addition Apple has finally allowed for third party widgets to appear in the Notification centre.
'Spotlight' has seen a few changes too. Clicking on the small magnifying glass in the toolbar now brings up a search bar in the centre of the screen, when typing Spotlight will search the web for results rather than just files on the hard drive.
Mail and Safari have new features too. In Mail users can now send file attachments of up to 5 gigabytes; the attachment is sent via iCloud to avoid the receiver's inbox rejecting the email. There is also a new Mail feature called 'MarkUp' that will allow the user to doodle on any attached image.
Safari's interface in Yosemite has been completely redone with cleaner and more simplified toolbars and icons. Users can now open a private browsing window with normal windows in the background; also there are more options to share webpages.
Continuity appears to be the biggest new feature of Yosemite. Continuity keeps all of your Apple iDevice working together without a hitch. A hotspot can be created with AirDrop that now works between iOS and Mac. Then if you start typing an email on your iPhone for example but then decide to switch to Mac, you will be able to put your iPhone to sleep and continue typing the email on your Mac without having the start over.
For the first time you can also receive and make messages and phone calls to people with or without an iPhone on the Mac. So if your sitting at your Mac and you get a call but your iPhone is in the other room you can accept the call on the Mac.
OS X Yosemite will be available to all Mac users free of charge later this year. Those who want to get it early can enter into the beta programme via Apple's developer website.