Question
In DevOps engineering you hear the term "build", what is it?
Answer
A build is usually a binary file which is an executable application. In DevOps engineering a build is usually compiled from a specific version of source code. In the context of Jenkins it is the "[r]esult of a single execution" of a Jenkins project (previously known as a Jenkins job). In the context of the modern and popular 12 Factor Application methodology, the build process should be separated from the run process (taken from https://12factor.net/). There are instances when the build process is closely tied to an application's execution; this would diverge from the 12 Factor Application process.
For a definition of the "build process" see this posting. To read other definitions, see these external sites:
https://searchsoftwarequality.techtarget.com/definition/build
https://www.techopedia.com/definition/3759/build
https://en.wikipedia.org/wiki/Software_build