What is an asset type id?

I’ve been messing around with Roblox API recently and came across an API that allows you to get a user’s inventory based off an asset type. I don’t really know what it means when it’s asking for an asset type id. Could somebody tell me what that is?

The api can be found here: https://inventory.roblox.com/docs#!/Inventory/get_v2_users_userId_inventory_assetTypeId

Figured it out over here: AssetType | Documentation - Roblox Creator Hub