What is the Difference Between iOS 4.3 and iOS 5?

The main differences between iOS 4.3 and iOS 5 include new features, improvements, and performance enhancements. Some of the key differences are:

Notification Center: iOS 5 introduced the Notification Center, which consolidates all notifications in one place, making it easier for users to manage and view their alerts.
iMessage: iOS 5 introduced iMessage, a new messaging service that allows users to send text, photos, and videos to other iOS devices for free, over Wi-Fi or cellular networks.
Newsstand: iOS 5 introduced the Newsstand, a dedicated app for managing and reading digital newspapers and magazines.
Reminders: iOS 5 introduced the Reminders app, which allows users to create and manage tasks and to-dos.
Twitter Integration: In iOS 5, Twitter integration was added, allowing users to easily share content and interact with their Twitter account.
Enhanced Camera Features: iOS 5 improved the camera features, making it easier to access and use the camera on iDevices.
Enhanced Photo Features: iOS 5 also introduced new photo features, such as photo editing and the ability to organize photos in albums.
Safari Performance: iOS 4.3 improved the performance of Safari, Apple's web browser, with the new Nitro JavaScript engine.
AirPlay Support: iOS 4.3 introduced improved video streaming and AirPlay support, allowing users to share content from their iDevices to other compatible devices.
iTunes Home Sharing: iOS 4.3 added iTunes Home Sharing, a feature that allows users to access their iTunes library from other devices on the same network.

Overall, iOS 5 brought a range of new features and improvements, while iOS 4.3 focused on enhancing existing features and functionality.