The Oxford English Dictionary defines peer review as:
"The process by which an academic journal passes a paper submitted for publication to independent experts for comments on its suitability and worth; refereeing" (Oxford English Dictionary, 2022).
However, you can double check whether a journal is peer reviewed by searching the journal title in Ulrich's. This is helpful as Compendex Engineering Village does not have a filter for only peer reviewed articles. Within Ulrich's, search for the journal title. If the referee's jersey appears next to the title, then the journal has gone through the peer review process.
For a good overview of the components of an academic article, see Anatomy of a Scholarly Article.