What is Android Market?

What is Android Market?
Is an online software store developed by Google for Android devices. An application program ("app") called "Market" is preinstalled on most Android devices and allows users to browse and download apps published by third-party developers, hosted on Android Market. Users can also search for and read detailed information about apps from the Android Market website.

Google announced the Android Market on 28 August 2008, and made it available to users on 22 October 2008. As of May 1, 2011 the Android Market had 294,738 apps and the Apple App Store had 381,062, but in April 2011 Android had 28,000 new apps, whereas Apple had 11,000 new apps. Distimo forecasted that the number of Android apps would surpass Apple apps before the end of July 2011, whereas Germany-based research2guidance forecasted Android apps to surpass Apple apps in August 2011 at 425,000 apps. 

Apps requested through the Market web page are downloaded and installed on the registered Android device. 

In May 2011 Google added new app lists to the Market, including "Top Grossing" apps, "Top Developers", "Trending" apps, and "Editors Recommendations".

Market application restrictions
The Android Market application is not open source. Only Android devices that comply with Google's compatibility requirements are allowed to preinstall Google's closed-source Android Market app and access the Market, subject to entering into a licensing agreement with Google. 

Availability for users
As of May 2011 users in 131 countries can purchase paid applications from the Android Market. Some carriers offer direct carrier billing for Android Market app purchases. There is no requirement that Android applications be acquired from Android Market. Developers in 29 countries can sell applications on the Android Market.

Application security
Android devices can run applications written by third-party developers and distributed through the Android Market or one of several other application stores. When an application is installed, the Android Market displays all required permissions. Google started remotely removing the malicious apps from infected devices on March 5, and also released its own app, the "Android Market Security Tool March 2011", which automatically removed the exploit.