Vanilla and Rise and Fall
The Research Lab is a high-level building that boosts a city's Science output. It provides +4 Gold with the Third Alternative policy card (as well as +2 Culture in Gathering Storm), so if you're aiming for a Science Victory and have many cities with Research Labs, you may want to gear your civic development toward discovering Totalitarianism even if Fascism isn't your government of choice.
The Research Lab also increases the yields of specialist slots, so make sure you work those after building it - that is, if the city is only there to generate Science. That is the case more often than not if you're going for a Science Victory.
A research lab is an institute devoted to the advanced study of a subject, which might be medicine, physics, chemistry, robotics, clean energy, or new products for TV infomercials. Such labs may be publicly funded or run by wealthy corporations looking for profits; research labs may be attached to universities or they may be independent of academic boundaries and ethics. It is pretty clear that “efficient” research labs are the future of research in every discipline. As civilization’s understanding of the world has advanced, the days of the dedicated scientist working alone in his or her basement and shouting “Eureka!” have all but passed. Whatever understanding we may gain of the natural world, whatever new tech toy may grab our attention, whatever improvement of our daily life may come, whatever horrors may be unleashed, it will likely come out of a research laboratory, whether large (CERN’s Large Hadron Collider) or small (computer simulation modelling).