The first principle is "Our highest priority is to satisfy the customer through early and continuous delivery of valuable software."
From that follows that all Agile Processes need to be inherently iterative.
Then can some one explain how UP, RUP & XP fall in the whole scheme of things
UP is a framework for iterative processes. RUP is the commercial version of the UP. It is possible to tailor Agile processes from RUP, but most teams seem to end up with rather plan-driven, communication-through-documents ones.
XP is the most popular Agile process. Technically it could be seen as an instance of RUP, though I'd say that there isa rather big disconnect in culture.
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus