please explain this oracle syntax

[sdasavi]

HI
Can any one explain the usage of orchestrate in this below syntax.

UPDATE
source1
SET
col1 = orchestrate.col1 , col2 = orchestrate.col2 , col3 = orchestrate.col3 , col4 = orchestrate.col4 , col5 = orchestrate.col5

[chulett]

Bind variables.