Mainstream Economics
  
Just as there are mainstream movies, clothes, and hip 'n' trendy stores at any given time period...mainstream economics is also a Thing.
Mainstream economics encompasses the economic schools of thought that are currently in vogue, including both micreconomics and macroeconomics.
As much as economists would like economics to be more of a hard science than a social science...because math is nice...it’s definitely a social science. Time and again, studies show that people aren’t rational. We’re dealing with other people, expectations, and emotions…and that stuff is hard to predict.
Today, neoclassical economics is top dog. It's mainly concerned with trade-offs, supply and demand...things you definitely learned in economics 101.
Heterodox economics (the opposite of mainstream, or orthodox economics) is growing, as new problems (that neoclassical economics doesn’t address) are growing threats to society...like climate change and nuclear war and...stuff.