Schools, universities and labs produce research points daily; points and money flow together into the selected research. Open the tree in the R&D tab, pick a target — progress runs by itself.
Pick for your economy: production line (Automation → Robotics → AI) if you are industrial, the energy branch if you have an energy gap, the education branch if labor is scarce. Early on, cheap low-tier nodes pay off fast.
With the switch at the bottom of the Research tab on, the shortest available node starts by itself whenever the bench falls idle, and the next one follows. Turn it off when you want to steer the tree yourself.
Finish the related research and the Robotic/AI version of the same building appears in the build list: far less unskilled labor, higher output — in exchange it consumes robots or chips. The corner badge on the icon marks the version.