The part of income after tax that is not consumed is defined as

The part of income after tax that is not consumed is defined as saving. Saving refers to the portion of income that is not spent on immediate consumption and is instead put aside for future use.
When we receive our income, we typically have various expenses to cover, such as bills, groceries, and entertainment. After deducting these expenses and taxes, we are left with a certain amount of money. If we choose not to spend this remaining amount and instead keep it for later, we are saving that money.
Saving is important because it allows us to build up financial security and prepare for unexpected expenses or future goals. It can also be used for long-term investments, such as buying a house or planning for retirement.
In summary, saving is the part of our income that we choose to set aside rather than using it immediately for consumption.