Answer:
A period in which the economy is growing at a rate significantly above normal.
Step-by-step explanation:
The economy experiences relatively fast growth during the expansion process, interest rates continue to be small, output rises and inflationary pressures are building up. Once the economy reaches a low point, the cycle peak is reached, and development starts to recover.
Expansion is sometimes described as the first step in the business cycle, but this is an arbitrary point of departure, here the economy has a constant stream in the supply of capital, and the investment booms.