An oracle is a modal/standard used by software testers and software engineers to make sure whether a implemented feature has passed or failed for the utmost quality. It is used by comparing the output(s) for a very same given test case input, to the outputs that the oracle determines that product should have.
In a simplest way, for specific time duration, a system which instigates, considers, assesses, assures and answers the questions, need and dilemma regarding a particular field of that time duration is called the Oracle. Oracle transforms from door to door of time. In a nutshell, as generation goes, Oracle is updated and will be updated by the pressure of user(s) demand. Whatever Analyst, QA, Developer or other experts, each and everyone must follow the Oracle to set up all requirements.
Have a look on the end edge of each line altogether. For MS Word it looks like smooth stair without any disruption but for Wordpad it is not. It was true in the age of Wordpad that it was the model for next version - it was Oracle for that time period. Now, we need to update this Oracle to MS Word as it is much more solvent with more options than Wordpad.
Above all are examples of word processing editors, among these last two are web based. WOW!!. But this WOW must not stand stop here. These existing products have lots of limited dimension. As a consequence, new WOW will be coming soon but those will be based on running Oracle. So we must update Oracle day by day by absorbing i-knowledge.