Apple Inc.'s iOS 5 operating system, which will power iPhone 3GS, iPhone 4, iPod touch 3rd generation, iPod touch 4th generation, iPad, iPad 2 and iPhone 4S, is going live from Wednesday.

All the new devices sold after Oct. 12 will have iOS 5 pre-loaded while an upgrade software is available for the current users from the iTunes store. The software update is free and brings more than 200 new features to the iPhone, the iPad and the iPod Touch, including a location-aware reminders app, newsstand and wireless syncing.

The most important iOS 5 features were announced by Scott Forstall during the WWDC 2011 keynote address. A few of the features inside iOS 5 have been uncovered at the event. However, most of the features already existed in Google's Android operating system.

The Cupertino programmers have taken bits and pieces from their competitor, applied the customary layer of fit and finish, and polished the experience to a shine. Here is a look at all the features of iOS 5.

Notification Center: The users can get to notification center by just swiping the finger down from top and access the entire notifications store in one place. Furthermore, new notifications can be viewed and attended to directly from the Lock Screen, making for quick and easy access. This feature includes new notification system, improved app notifications at the top, lock screen notifications, notification options to choose for each app and notification sorting by app, time etc.

iMessage: iMessage, which Apple's new free text messaging service, lets people communicate in real time. Users can send text messages, photos, videos, contacts, group messages, and more, from any iDevice. This service is very similar to BlackBerry Messenger, which allows users to send unlimited texts to anyone who own similar devices. With wireless syncing, users can start a conversation on one device and continue it on another, and can also track their messages further with delivery and optional read receipts. iMessage works for sending texts, photos, locations, and contacts.

Newsstand: The OS organizes users' magazine and newspaper app subscriptions in Newsstand, a folder that lets user access favorite publications quickly, easily, and automatically updates with latest issue.

Reminders: Reminders, which is supported by geolocation feature, is a location-based organization tool that aims to offer improved to-do lists that are compatible with iCal, Outlook and iCloud.

Twitter Integration: Apple is bringing deep Twitter integration to all of its iOS-based devices and to many of its own apps, including Camera, Photos, Safari and Maps. That integration also, of course, extends to Contacts, where you'll be able to link your contacts to their Twitter handle and keep their information updated accordingly.

AirPlay Mirroring: AirPlay now supports video mirroring, which can be wirelessly streamed whatever is on iPad 2 or iPhone 4S to HDTV via Apple TV. Even if the device is rotated from portrait to landscape or zoom in and out, it could be visible via Apple TV.

iCloud: iOS 5 will be the first platform to run on Apple's new cloud infrastructure called iCloud. iCloud is a free service and users get 5 GB by signing up, but users can buy more storage if they so choose. By plugging into a power source, iCloud automatically pushes all documents, apps, calendars, mail, contacts, photos, and music to all of the user's other iOS devices.

Camera: The new operating system on iOS 5 gives access to camera button right on your lock screen. Users can now capture a photo by simply tapping the Home button twice. Users can also open the camera app directly from the Lock screen. The can pinch the screen to zoom, tap the screen to focus and can now shoot photos with a click of the + volume button. This feature includes open camera app, take pictures, camera grid, pinch-to-zoom, one tap auto focus and auto exposure, lock auto exposure and auto focus for consistency.

Photo Enhancements: This feature includes Swipe left to open camera roll, crop photos, enhance color tones of photos, rotate photos, red-eye removal, photo stream, and organize photos within camera roll. Without the photo editing software on a computer, the user could turn snapshots into frame-worthy photos in just a few taps. Crop, rotate, enhance, and remove red-eye without leaving the Photos app.

Safari: This feature includes tabbed browsing in Safari, which is only for iPad, Safari reader similar to RSS reader, Safari reading list, which can be used for saving Web pages for offline reading, improved performance, private browsing, and Web site specific data can be deleted. Safari Reader displays Web articles sans ads or clutter so the user can read without distractions.

PC Free: With iOS 5, the user doesn't need a computer to own an iPad, iPhone, or iPod touch. The iOS device can be activated and set up wirelessly, right out of the box without a Mac or PC. 

OTA updates: For the Over-The-Air (OTA) Updates, there is no need for a computer and cord. The iOS 5 devices can now self-update the system software right on the device itself through Wi-Fi or 3G. Users don't have to download and install entire OS as delta software updates are enabled.

Mail: Users can write in rich text, indent paragraphs, flag important messages, and search the archive in the body of messages. With iOS 5, users can search mail, conversations as well as drag and drop addresses.

Calendar: In Calendar, it is easy to create, manage, and view events. iCloud syncs calendars to other devices, and even with select family and friends. The user gets more perspective on schedule with year view on iPad and week view on iPhone and iPod touch.

The user has to tap for creating an event and has to drag adjust the time and duration. Add, rename, and delete calendars directly from the user's device. This feature includes custom tones for events, year view only on iPad, week view for iPhone and iPod, Swipe-Left to browse through day-view, current time on Calendar if in landscape mode, notification center displays Calendar tasks and if mail was disabled, the user would receive calendar invites with notifications.

Game Center: iOS is the world's most popular gaming platform. With iOS 5, users can get game face on with even more Game Center features. The user can post a profile picture, and meet the match with new friend recommendations based on the games he/she plays. New games can be discovered without leaving Game Center. This feature includes profile picture, friend recommendations, game recommendation, friends-of-friends list, app store, new achievements, play turn-based games, delete saved games, and backup game saves in iCloud.

Wi-Fi Sync: Users could wirelessly sync their iOS device to Mac or PC over a shared Wi-Fi connection. Every time a user connect iOS device to a power source, it automatically syncs and backs up any new content to iTunes.

Multi-tasking Gestures for iPad: iOS 5 includes a few new moves and shortcuts to help users get around even quicker on iPad. Using four or five fingers, swipe up to reveal the multitasking bar, pinch to return to the Home screen, and swipe left or right to switch between apps.

Accessibility: iOS 5 comes with innovative new features that make it easier for people with mobility, hearing, vision, and cognitive disabilities to get the most from their iOS devices. iOS 5 works with specialized hardware accessories. The LED flash and custom vibration settings let a user see and feel when someone's calling. And improvements to VoiceOver include custom element labeling.

Parental Controls: The new system has built-in parental controls to manage use of Safari, Camera, FaceTime, Game Center, Location Services, YouTube, the iTunes Store, the App Store, and more. Parents can also lock the settings so kids can't go in and change them later.

App Store: With thousands of apps in practically every category, iOS is the platform for the world's largest collection of mobile apps. Apple gives third-party developers a rich set of tools and APIs, and they've created apps and games that redefine what a mobile device can do. Just browsing the App Store on iPhone can let you download them with a tap on the screen.

Safety: iOS is highly secure from the moment a user turns on the device. All apps run in a safe environment, so a Web site or app can't access data from other apps. iOS also supports encrypted network communication to protect the user's sensitive information. The user could set a passcode lock to prevent unauthorized access to the device and configure the device to delete all the data after too many unsuccessful passcode attempts. And in case a device is lost or stolen, 'Find My' device allows the user to locate it on a map and remotely delete all the data.

Locate Alternate Routes in Maps: One of the many new features of iOS 5 is that Google Maps has been updated to display multiple route directions. Previously, this was not possible in iOS.

YouTube: YouTube on the iOS 5 will now stream high definition (HD) video over 3G. The user can only get high quality video over YouTube if he/she are on Wi-Fi.

Additional Apps: iOS 5 comes additional apps that includes a new music app for iPad, separate music and video app for iPhone, scroll for long song titles, song description, smart playlists, improved sound check for music, weather, Twitter pictures, personal dictionary, built-in dictionary, iTunes Tone store, new keyboard shortcuts, silent switch, Arabic language support for VoiceOver, Assistive Touch Gestures, FaceTime over 3G, FaceTime without SIM card, social networking integration, and help center.