Templates are special items that won't appear ingame, they are used as properties holders for other items.
They allow you to write common properties in one item and add them automatically to other items without constant copy and paste.
To create a template you have to set template: true in your item.
This is an experimental feature, let me know if something is not working correctly.
You can see an usage example in this addon.
What are variants?
Variants are items that will appear ingame and will inherit properties of template items.
To create a variant you have to set variant_of: template name in your item.
Example
I want to create multiple furnitures which are equal but with different model.
template_wood_park_bench:template:true# <---- HERE you can see I set this item as "template"display_name:""lore: - 'lore-decorative-item'resource:material:PAPERgenerate:falsemodel_path:item/oak_wood_park_benchbehaviours:furniture:entity:armor_standsmall:truesolid:truefixed_rotation:truehitbox:length:1width:2height:1width_offset:0.5placeable_on:walls:falseceiling:falsefloor:truefurniture_sit:sit_height:0.5sit_all_solid_blocks:trueoak_wood_park_bench:variant_of:template_wood_park_bench# <-- HERE I specify the template to inheritdisplay_name:"Oak wood Park Bench"permission:oak_wood_park_benchlore: - 'lore-decorative-item'resource:material:PAPERgenerate:falsemodel_path:item/oak_wood_park_benchspruce_wood_park_bench:variant_of:template_wood_park_bench# <-- HERE I specify the template to inheritdisplay_name:"Spruce wood Park Bench"permission:spruce_wood_park_benchlore: - 'lore-decorative-item'resource:material:PAPERgenerate:falsemodel_path:item/spruce_wood_park_benchbirch_wood_park_bench:variant_of:template_wood_park_bench# <-- HERE I specify the template to inheritdisplay_name:"Birch wood Park Bench"permission:birch_wood_park_benchlore: - 'lore-decorative-item'resource:material:PAPERgenerate:falsemodel_path:item/birch_wood_park_bench