Air is an invisible, non-solid block that occupies any space not filled by another block. It allows entities such as players and mobs to move freely through it. This block is automatically generated wherever there are no other blocks, making it the default filler in the world. It cannot be collected or interacted with directly, but it is essential for the mechanics of placing blocks and the flow of liquids.
The numerical item ID for Air is 0
Numerical item IDs will only work in Minecraft versions below 1.13.
The item ID for Air is minecraft:air
This is the spawn command to give yourself Air in Minecraft which includes the Minecraft /give command. If you are using the Essentials plugin you will need to use /minecraft:give instead of /give