What is the difference between the 3rd generation and 4th generation processors?

kindly tell me the brief difference between the 3rd gen and 4th gen Pcs or laptops???

whats the technology difference between them??

etc etc ..........

Only Difference Between 3rd & 4th Gen Is Integrated GPU and power efficiency nothing els, basically 4th Gen designed for laptops in mind

armada has provided a useful summary.

If you want to read a basic and brief introductory document, then check this 9-page document produced by Intel (pdf file; size: 615 KB): https://software.intel.com/sites/default/files/introduction-to-intel-4th-generation-core-processor.pdf

If you are interested in benchmarks, check these two links:

Tested: Intel's Haswell CPU On The Desktop
http://www.tested.com/tech/pcs/455882-tested-intels-haswell-cpu-desktop/

The Haswell paradox: The best CPU in the world… unless you’re a PC enthusiast
http://www.extremetech.com/computing/157337-the-haswell-paradox-the-best-cpu-in-the-world-unless-youre-a-pc-enthusiast