History: What is decay time in reverb?

What is decay time in reverb?

• Decay time sets how long the reverberation will sound for.
  Correct!
• Decay times are the initial, loudest reverberations.
  That is early reflections.
• Decay time is the amount of time between the original source and the start of reverberation.
  That is predelay.
• Decay time will impact the number and intensity of the reflections.
  That is ratio and depth.