Knowing the version of Android that you have will give you information about what your device is capable of and also which applications are compatible with it. The applications in the Market place with better software development methodologies will state which versions of Android they have tested their application in. If you do not know which version you have it is advisable that you find this out.

Android is Google's entry into the mobile operating system realm. It is a very extensible system that provides as much user configuration as possible. The operating system itself runs on a lightweight linux kernel, and is open source. This combination allows for simple development and extendability to the operating system using the Java development language.