TL; DR: Positive Computing is understanding how computing can make normal people happier.
Psychology started life as a science dedicated to helping people reduce mental illness. Recently some psychologists wondered how their craft could help normal people be happier. This new branch of psychology is called positive physiology.
Similarly computing started life dedicated to making people be more productive. Many early computer engineers expected the increase in productivity to increase happiness. But, while productivity soared, happiness remained flat. Recently some computer engineers wondered how their craft could help normal people be happier. This new branch of computing is called positive computing.
Positive computing is a brand new field, and I look forward to investing in it heavily. If you want to go deep into positive computing, there are some resources below: