America's Department of Energy "has started a new Office of Nuclear Energy projects called the Advanced Reactor Demonstration Program" (or ARDP) reports Popular Mechanics:
"The $230 million program will give $160 million to scientists working on two reactor designs that 'can be operational' in the very near future." The "Advanced" part of ARDP is an industry term for the generation of reactors we have today... Generation IV — the super advanced reactors? — are in the research phase, but the ARDP statements mention development into the mid 2030s and likely includes generation IV. So the technical difference may be arbitrary, but the advanced reactors are often safer, smaller in overall form factor, and more standardized in order to be easier to install and scale.
Most existing power plants are idiosyncratic, built on a case-by-case basis to suit individual communities or use cases. A more uniform process means plants that are easier to secure, support, and regulate. One of the leading projects the Nuclear Energy Institute (NEI) mentions may sound familiar: "NuScale Power LLC is expected to receive the first small modular reactor design certification from the U.S. Nuclear Regulatory Commission later this year," the NEI reports. NuScale's tiny modular reactor is designed to be deployed for small communities with lower power needs and embodies advanced reactor values. (NuScale received previous funding and is not eligible for this program.)
This is a good development by Donald Trump Administration to make a paradigm shift from petroleum to other sources of energy.