Hi Navin, keyword framework has largely come from the need of enabling manual test engineer to write automate tests. As the name suggest there would be key words associated with different operations on automated test script, for example click, type etc. And these keywords would be used by manual testing team to design automated test in the same way as writing manual tests. There would always be programmatic implementation behind these keywords but manual testing team does not have to aware of it.
Though it may look promising on surface, it is not very beneficial in reality, for example there would be need to maintain keywords and not all operations might be supported through keywords. The more emphasis seems to be on letting manual test engineer with good domain knowledge to write string tests and having a different automation test engineers.
~ seleniumtests.com