what is the name of the world of warhammer 40k

The world of Warhammer 40,000 is usually called the Imperium’s galaxy- spanning setting , but the central human homeworld is Terra —often referred to as Holy Terra. The broader fictional universe itself is commonly just called the 40k universe or the galaxy of Warhammer 40,000.

Quick distinction

• Holy Terra : the Emperor’s throneworld and humanity’s most important planet in the setting.

• The Warhammer 40,000 setting : the entire galaxy where the story takes place.

• The Imperium of Man : the main human empire spread across that galaxy.

If you meant the name of the main planet , it’s Terra.