Use of resources--the file system and networking--needs to be managed securely and needs to be accounted for. A node might want to allow netlets file system access, for example, but not use its local file system. By using particular patterns a Jtrix node can achieve this with minimal confusion for the netlets.
Here we look at how this is achieved with Nodality, plus how to embed a non-Jtrix application into a Jtrix environment.
All this is specific to Nodality. Some Jtrix applications will not run directly on Nodality; they will run on a hosting service which may or may not run on Nodality. In those cases the hosting service will give you resource access and manage them for you. The details here are lower level.
As a final aside, most serious applications are expected to use the resource management features of a hosting service, and if we build an application with the Beatrix framework, which uses that, then this becomes even easier. In these cases our application will run with any hosting service that implements the right interfaces. Node implementation becomes irrelevant.