Editing Oracle machine (section)

{{short description|Abstract machine used to study decision problems}}
{{for|computing equipment sold by Oracle Corporation|Oracle Corporation#Hardware}}
{{More footnotes needed|date=October 2023}}
{{Use dmy dates|date=October 2023}}
{{Black-box}}

In [[computational complexity theory|complexity theory]] and [[computability theory]], an '''oracle machine''' is an [[abstract machine]] used to study [[decision problem]]s. It can be visualized as a [[black box]], called an '''oracle''', which is able to solve certain problems in a single operation. The problem can be of any [[complexity class]]. Even [[undecidable problem]]s, such as the [[halting problem]], can be used.