Discretionary Income

What Does Discretionary Income Mean?
The amount of an individual's income that is left for spending, investing or saving after taxes and personal necessities (such as food, shelter, and clothing) have been paid. Discretionary income includes money spent on luxury items, vacations and non-essential goods and services.  

Discretionary income is derived from disposable income, which equals gross income minus taxes.  

Investopedia explains Discretionary Income
Aggregate discretionary income levels for an economy will fluctuate over time, typically in line with business cycle activity. When economic output is strong (as measured by GDP or other gross measure), discretionary income levels tend to be high as well. If inflation occurs in the price of life's necessities, then discretionary income will fall, assuming that wages and taxes remain relatively constant. 

Discretionary spending is an important part of a healthy economy - people will only spend money on things like travel, movies and consumer electronics if they have the funds to do so.  Some people will use credit cards to purchase discretionary goods, but increasing personal debt is not the same as having discretionary income.