What is the difference between QTP and UFT ?

HP Unified Functional Testing (UFT) is a new tool released in December of 2012 that integrates two of HP Testing products in a common IDE.It provides a power full testing framework for GUI and API testing:

• HP Service Test
• HP QuickTest Professional

HP Unified Functional Testing has enhanced and brand new functionalities that are not available in previous versions of HP Service Test or HP QuickTest Professional.

Some important considerations.

• HP Unified Functional Testing offers integration with Perfecto Mobile in order to perform Mobile Testing.
• HP Unified Functional Testing offers new Add-ins for GUI testing as such as: QT and Flex.
• HP Unified Functional Testing is not considered to be newer version of either QuickTest Professional or ServiceTest.
• Many of the knowledge base articles available for HP QuickTest Professional 10, 11 and HP Service Test 11.20 can be applied to HP Unified Functional Testing product.
• Licenses for QTP or ST will work for UFT, but they can restrict some features. 
• If you just need API Testing, you can use HP Service Test Standalone, however this option it’s not available for GUI testing.