Version 3 of ITIL was released in spring of 2007 and differs from Version 2 in its approach. Where Version 2 focuses on aligning business units with the IT organization using technology-oriented processes, Version 3 has a much stronger business focus and promotes IT integration into the business units. ITIL 4 has managerial approach in it.
ITILv 3 has 26 processes . Processes don’t run by themselves. They need people to carry out the individual process activities. And the people the processes look for come from functions. Functions provide the resources needed by the processes to complete their objectives. ITIL 4 has 34 practices no processes. Service lifecylce in ITIL v3 is defined as Service Value System in ITIL 4.
ITIL 4 is a framework, no prescribed processes. However it does not mean that we cancel ITIL v3 processes and not valid anymore. We can still use them and incorporate into our ITIL 4 practices within our company. They would best fit when tailor made. In ITIL 4 you do not have to worry about strict observace of processes you are free to tailor them to your need.