HTML (Hypertext Markup Language) is a popular web-based language used to create websites and webpages. However, it is not used to create Android mobile applications because it does not provide a native user experience. Additionally, HTML is not optimized for mobile devices and its webpages are often bloated and contain a lot of unnecessary code, causing them to load slowly and be unresponsive. For those looking to create an Android application, a better option is to use a language such as Java or Kotlin.