Your Android smartphone is a computer in and of itself; as such, it runs with an operating system installed. You install programs on your smartphone the same way you install them on your computer, although the process is more complicated. Today, we want to explain the types of files that the Android operating system uses to install apps on your phone, as well as why it might be a good idea to let the Google Play Store do the hard work for you, in terms of locating and installing apps.