Rational unified process

I would like to start with waterfall model.This model has been adopted from construction engineering.As softwrae development is also an engineering but it is different from all othe engineering in terms of building software.To deal with people for requirement gathering is most critical thing.
Waterfall model is a staged construction model.In which each phase build some concrete artifict and it requires comprehensive documentation.
There are phases like requirement gathering,design,implementaion,verification and maintenance.
Waterfall model is useful when requirements are freezes in early phase.

Now talk about RUP(Rational Unfied Process).If we look history Rational Corporation is hired b y IBM.Rational corporation followed s/w development process called as Objectory process.Then it has been called rational Objectory Process.
So finally IBM come up with Rational Unified Process with best practices followed by organization.
RUP consists of different nine disciplines.Among them six are engineering and three are support disciplines.