Integrate review feedback into Packages section

Author: catamorphism

component-model/src/design/packages.md

@@ -1,18 +1,23 @@
 # WIT Packages
 
-A **WIT package** is a set of one or more [WIT (Wasm Interface Type)](./wit.md) files
+A **WIT package** is a set of one or more [WebAssembly Interface Type](./wit.md) (WIT) files
 that, taken together, contain a set of interfaces and worlds that are related to each other.
-WIT is an IDL (interface definition language) for the component model.
+WIT is an [interface definition language][wp-idl] (IDL) for the component model.
 Packages provide a way for worlds and interfaces to refer to each other,
 and thus for an ecosystem of components to share common definitions.
 
-A WIT package is like a namespace for grouping related interfaces and worlds together
+A WIT package groups related interfaces and worlds together
 for ease of discovery and reference.
-A package is not a [world](./worlds.md).
+A package is not a [world](./worlds.md): a package maps to one or more files
+and contains worlds.
+A world is a bundle of imported and exported types and interfaces.
 
 * The WebAssembly System Interface (WASI) defines a number of packages,
   including one named `wasi:clocks`.
-  Our HTTP proxy world could import the `wall-clock` interface from the `wasi:clocks` package,
+  Our HTTP proxy world could import the `wasi:clocks/wall-clock` interface
+  (read as "the `wall-clock` interface from the `wasi:clocks` package"),
   rather than having to define a custom clock interface.
 
 > For a more formal definition of what a WIT package is, take a look at the [WIT specification](https://github.com/WebAssembly/component-model/blob/main/design/mvp/WIT.md).
+
+[wp-idl]: https://en.wikipedia.org/wiki/Interface_description_language