docs: describe GSB (#120)

arch-snapshot/arch.md

@@ -645,8 +645,46 @@ to be more of a chore than a useful security mechanism, so Accounts became
 equivalent to Identities.
 
 ### GSB
-* what it is, how it works and how it imposes a code structure and how
-  addressing works
+
+Golem Network is built using a custom distributed component model known as
+the **Golem Service Bus** (GSB). Functionally, it is similar to technologies
+like [Windows
+DCOM](https://en.wikipedia.org/wiki/Distributed_Component_Object_Model),
+[CORBA](https://en.wikipedia.org/wiki/CORBA), and
+[UNO](https://en.wikipedia.org/wiki/Universal_Network_Objects). In a nutshell,
+this model mans that:
+* Applications are built by composing these self-contained components, which
+  encapsulate specific functionality.
+* Each component exposes a well-defined interface, enabling interaction with
+  other components without exposing internal details.
+* Components can be accessed and invoked using a consistent method, whether they
+  are local or remote.
+* The caller doesn’t need to know where the component resides (e.g., in the same
+  process, on another machine) or manage its lifecycle directly.
+
+Key characteristics of GSB include:
+* **Language specificity**: GSB is not language-independent. While it is
+  theoretically possible to create compatible implementations in other
+  languages, only a Rust implementation currently exists. No formal effort has
+  been made to specify or develop implementations beyond Rust.
+
+* **Prefix-based component responsibility**: In GSB, components are addressed
+  by paths. Components can be responsible not just for a single path but for all
+  paths that share a certain prefix. This design allows the path itself to carry
+  additional payload information, enabling flexible and dynamic routing. Users
+  provide GSB with a path, and the process forwards the entire path to the
+  component mapped to the matching prefix.
+
+* **Absence of remote service concepts**: GSB does not distinguish between
+  local and remote services. Instead, a dedicated component, called
+  [Net](#networking), is responsible for forwarding traffic to remote targets.
+  The target’s address is specified within the path, and the Net component
+  [uses this address](#gsb-prefix-mappings) to direct the payload to the
+  appropriate remote destination. It then removes the address prefix from the
+  path before forwarding the remaining path (and payload) to the destination.
+
+Except for the above, most intuitions from the listed similar technologies
+should apply.
 
 ### Networking