In short
GS1 is the international organisation that manages barcode and data standards for globally unique identification of products, locations and logistic units.
GTIN (product number), GLN (location number) and SSCC (logistic unit number) are GS1 standards. Application Identifiers (AIs) mark fields such as (01) product, (10) lot, (17) expiry and (21) serial number.
GS1-compliant labelling is the basis for traceability across the supply chain and automated data exchange with customers.