Next to the application name, the extension counts the number of the application's build configurations and its build contexts. Each build context is a part of the application configuration that serves a single purpose defined by the build system.
Note
The build context is a term specific to the extension; it is not used in the nRF Connect SDK or Zephyr.
Let's have another look at the image used earlier on this page.
The application hello_world_3 has two build configurations (build and build_1).
build does not use sysbuild or child images, so in this case this single build configuration is also a single build context.
build_1 is a build configuration created with sysbuild and it is also a build context, similarly to builds without sysbuild.
However, sysbuild configuration can include multiple images, each of which is also considered a separate build context.
On the above image, build_1 includes a single image (context) hello_world_3.
In other words, the hello_world_3 application has three contexts (build, build_1, hello_world_3) split between two build configurations (build and build_1).