What does my world parkour d4 mean?

This is a parkour game.

According to the query on the steam platform, the phrase "My World Parkour d4" means that players play parkour mode in the game "My World", in which "d4" is a special prop in the game, usually called "instant skateboard", which can jump and slide on the ground or in the air and move at an extremely fast speed, which is very suitable for parkour mode.

In addition, in the parkour mode of My World, you can also play online, and players can play with friends.