The technical time required for one's body to replenish itself of fluids, to be able to ejaculate semen.
This 'Recovery Period' is where the body, most notably males, is unable to achieve ejaculation, and can also be a period where further stimulation may become painful.
It is due to the production of certain chemicals within the body, which are needed to produce the ejaculate or are produced in the ejaculation stage.
On average, males require about a half hour to regenerate.
Younger males, about eighteen may only need fifteen minutes, while men in their later years, such as 70's, can require as much as twenty hours.
This 'regenerative' period varies from male to male, and can be a few minutes, to several days in duration.
Some women do not have a refractory period, which is why they can have multiple orgasms on top of each other.