== What is WebKit2 ? ==
WebKit2 is a substantial architectural enhancement to WebKit that allows clients/embedders of the framework to harness operating system (OS) level "features" for a more responsive and secure application. 
The "UI Process" is the application that uses the WebKit2 API C API to render web views. The "Web Process" are the one of the many processes that primarily run the web engine responsible for the downloading, parsing and rendering of content. 

The main upsides of WebKit2 for client applications are : 
   * more '''responsive''' application UIs that farm out CPU intensive web processing to a worker process
   * improved '''crash tolerance''' by isolating crash-prone code outside the UI process
   * better OS enforced '''security''' for memory accesses, file access, sensor access

For WebKit developers, the main changes are: 
   * easier memory management: memory leaks and resource leaks are forgiven when a worker process is closed 

== The multi-process browser landscape ==
[http://en.wikipedia.org/wiki/Internet_Explorer_8 Microsoft's IE8] and Google's [http://dev.chromium.org/developers/design-documents/multi-process-architecture Chromium Browser] was the pioneers in separating the UI process from the engine process. WebKit2 is the fully public domain implementation of the same essential architectural concepts.