Sorry you received unhelpful sass from other commenters. It stands for "Objective and Key Result" - it's a common "business-speak" initialism that basically translates to "a measurable, data-driven goal".
I'd say it's more than that. OKRs are a concrete framework that came out of Intel and was popularized by Google. But yes, the focus is on setting objectives backed by measurable results.
Can be a document, an app, whatever. One flavor is objectives are set at the top, their KRs are translated into objectives for the next management layer with their own KRs, and so on. It's an iterative process with some combination of top-down and bottoms-up activities. And afterwards, the results are reviewed. There's more to it, but that's the gist.
