In the lookup transormation mainly 2 types

1)connected 2)unconnected lookup

Connected lookup: 1)It recive the value directly from pipeline

                           2)it iwill use both dynamic and static

                            3)it return multiple value

                             4)it support userdefined value

Unconnected lookup:it recives the value :lkp expression

                            2)it will be use only dynamic

                            3)it return only single value

                             4)it does not support user defined values