Incapacitated¶
You cannot take an action, Bonus Action, or Reaction. Your Concentration ends and you cannot speak. If Incapacitated when rolling Initiative, you have Disadvantage on that roll. This condition by itself does not reduce Speed to 0.
Duration and overlapping effects¶
The effect that caused the condition determines its duration, removal, and any saving throws. If several effects impose the same condition, track each duration; its effects do not grow stronger merely because it was imposed more than once. Other conditions can still apply at the same time.
Source: supplied Player’s Handbook (2024), Rules Glossary. Paraphrased quick reference; specific rules can override these general rules.