Typically we would say retirement is a point where a person ceases employment completely. This is differernt from ceasing employment voluntarily (quitting) or involuntarily (fired or laid off).
Of course, we often think of employment as the condition of having paid work. So if you do volunteer work or focus on raising children or other ways of spending your time, other than paid employment, with no intention of ever taking up paid employment; are you retired?
Out of Retirement
If you cease employment completely (so you are “retired”) but decide to take up employment again at a later time, are you “unretired” or just employed again. Or is the paid work called your retirement job?
That is, you retired and elected to receive a pension. You then seek and gain employment and so have two incomes – one income for doing nothing and paid employment.
Why Retire?
Interestingly many cases of working in retirement have little to do with monetary status (although some do). Studies have shown after a lifetime of focusing on participating in paid employment, stopping suddenly can effect a big psychological impact, a negative one.
Suddenly stopping your paid employment has been shown to be a statistically valid causal factor in early demise.
Working in paid employment or unpaid employment (e.g. volunteering) provides a purpose . Leisure activies, technically not classified as work also provide a purpose.
In considering retirement, it is important to remember the key factor is not always financial. Although it is nice not to worry about income, the psychological impacts of not having a purpose or objective could be deadly.