Lab data
Lab data is the concept of collecting information in a closed environments, where outcomes won't unexpectedly be skewed by other conditions than those that were configured for running a test. In other words, Synthetic monitoring falls under lab data. Just like Lighthouse, lab data might help in specific scenario's, but will lack the answer and data from all your users out there.
In previous versions of PageSpeed Insights, Google was using this terminology. Next up are other lab data metrics that aren't part of the Web Vitals collection.