What is the difference between Shopify tags, metafields and metaobjects?

Tags are lightweight labels commonly used for organisation, automation and some filtering. Metafields store structured custom data on products, variants and other Shopify objects. Metaobjects let you create reusable structured content that can be referenced from multiple places. Use tags for simple classification, metafields for product-specific attributes such as material or care instructions, and metaobjects when the same structured entity—such as a designer, ingredient or size guide—needs to be maintained once and reused across the store.