Unconscious 5e condition

How the unconscious condition works in the 2014 rules (SRD 5.1) and the 2024 rules (SRD 5.2), what changed, and which spells and monsters cause it.

Unconscious in the 2014 rules (SRD 5.1)

An unconscious creature is incapacitated, can't move or speak, and is unaware of its surroundings.
The creature drops whatever it's holding and falls prone.
The creature automatically fails Strength and Dexterity saving throws.
Attack rolls against the creature have advantage.
Any attack that hits the creature is a critical hit if the attacker is within 5 feet of the creature.

While you have the Unconscious condition, you experience the following effects.

Inert. You have the Incapacitated and Prone conditions, and you drop whatever you're holding. When this condition ends, you remain Prone.

Speed 0. Your Speed is 0 and can't increase.

Attacks Affected. Attack rolls against you have Advantage.

Saving Throws Affected. You automatically fail Strength and Dexterity saving throws.

Automatic Critical Hits. Any attack roll that hits you is a Critical Hit if the attacker is within 5 feet of you.

Unaware. You're unaware of your surroundings.

The effects are the same. 2024 spells out Speed 0 and that you stay Prone when the condition ends; not speaking comes from Incapacitated.

From the SRD 5.1 spells: 4 spells can leave a creature unconscious.