In Zenject, Contexts are the glue between Containers and your Installers. This Unity tutorial covers the 4 Zenject Context types that are available in the framework.
In part 4 I covered Zenject Installers. Installers play an important role in dependency injection. They help the Container fill your application’s dependencies by telling it which objects to create.
Installers can be attached to one or more Containers. You attach an Installer to a Container via a Context. Each Context has access to a single Container.