Define FrameWork and Types of Framework?

Framework may be designed as a set of abstract concepts, processes, procedures and environment in which automated tests will be designed, created and implemented.this framework definition includes the physical structures used for test creation and implementation, as well as the logical interactions among those components.

It is Classified as
  1. First Generation Frame work
      a. Linear Frame Work
  2. Second generation Framework(hybrid Framework)
      b.Functional Decomposition
      c.Data Driven Framework
  3.Third Generation Frame Work
      d.Key word Driven Framework
  4.Fourth Generation Frame Work
      e.Model Based Frame Work.

For Detail:
http://www.automatedtestinginstitute.com/home/index.php?option=com_content&view=article&id=69:frameworks-introduction&catid=91:frameworks-introduction&Itemid=75