This is the most basic of the build item files, and it is the only file that must be present for every build item. We sometimes refer to this as the build item configuration file.

These are the files that direct abuild what to actually build in a given build item. Each build file is associated with a specific backend. Exactly one of these files must be present in order for abuild to attempt to build a build item. As such, these files are known as build files. When we say that a build item has or does not have a build file, we are specifically talking about one of these files. In particular, it is important to note that Abuild.conf and Abuild.interface are not considered build files. ^[10]

The Abuild.interface file is present for every build item that wants to make some product of its build accessible to other build items. We refer to this as the build item's interface file. There has been some confusion among some abuild users about the term interface. Please understand that abuild interfaces are distinct from Java interfaces, C++ header files, and so forth, though they serve essentially the same function. If you view a build item as an object, the abuild interface contains information about what services that object provides. It exposes the interfaces through which other build items will access a given build item's products.