How does a period of expansion differ from a period of contraction

The contraction period is the time during which tension develops in the muscle, and the relaxation period is the time during which tension is removed from the muscle. Expansion is the phase of the business cycle when the economy moves from a trough to a peak. Expansions last on average about four to five years but have been known to go on anywhere from 12 months to more than 10 years.