Updated Plugins section. (#8235)

- Minor update to remove some posisbly confusing discussion about
  pre 0.7 seperate binaries for plugins, and link to internal
  plugins section for more clarification of how plugins are
  handled in 0.7+.

website/source/docs/plugins/basics.html.md

@@ -19,22 +19,13 @@ this section of the documentation.
 
 ## How it Works
 
-The plugin system for Terraform is based on multi-process RPC. Every
-provider, provisioner, etc. in Terraform is actually a separate compiled
-binary. You can see this when you download Terraform: the Terraform package
-contains multiple binaries.
+Terraform providers and provisioners are provided via plugins. Each plugin
+exposes an implementation for a specific service, such as AWS, or provisioner,
+such as bash. Plugins are executed as a separate process and communicate with
+the main Terraform binary over an RPC interface.
 
-Terraform executes these binaries in a certain way and uses Unix domain
-sockets or network sockets to perform RPC with the plugins.
-
-If you try to execute a plugin directly, an error will be shown:
-
-```
-$ terraform-provider-aws
-This binary is a Terraform plugin. These are not meant to be
-executed directly. Please execute `terraform`, which will load
-any plugins automatically.
-```
+More details are available in 
+[Internal Docs](/docs/internals/internal-plugins.html).
 
 The code within the binaries must adhere to certain interfaces.
 The network communication and RPC is handled automatically by higher-level