E-commerce and marketplace integration glossary (ERP, PIM, feed, API)

E-commerce integrations are full of acronyms and technical terms. This glossary collects the concepts that recur in every multichannel project, explained clearly and with concrete examples.

Systems and roles

Term	Meaning
ERP	Back-office system: orders, warehouse, accounting. Often the authoritative data source.
PIM	Product Information Management: manages product attributes, descriptions and media.
OMS	Order Management System: orchestrates the order lifecycle across channels.
Middleware	Integration layer that connects systems and translates data.
Marketplace	Third-party selling platform (eBay, Amazon…).

Products and identifiers

Term	Meaning
SKU	Stock Keeping Unit: unique code for a sellable variant.
GTIN	Global product identifier (includes EAN/UPC).
MPN	Manufacturer Part Number: used when a GTIN is missing.
Variant	A version of a product for options like size or colour.
Feed	A file or stream describing products for a channel.

System-to-system communication

Term	Meaning
API	Interface that lets software exchange data.
REST	Resource- and HTTP-based API style, typically with JSON.
Webhook	A push notification sent by a system when an event occurs.
Polling	Periodic querying to check whether anything is new.
OAuth	Token-based authorisation standard.

Reliability and resilience

Term	Meaning
Idempotency	Repeating an operation yields the same result, with no duplicates.
Rate limit	The number of calls allowed within a time window.
Backoff	Increasing wait between attempts after an error.
Dead-letter	Queue of messages that could not be processed successfully.
Reconciliation	Comparing data across systems to verify consistency.

Data and synchronisation

Term	Meaning
Delta	Only what changed compared to the previous state.
Bulk	A mass operation on many items at once.
Mapping	Correspondence between fields/categories of different systems.
Overselling	Selling more units than available in stock.
Stock buffer	Safety margin to prevent overselling.

Conclusion

Mastering these terms makes it easier to design, communicate and evaluate an integration. They are the shared vocabulary of those working between ERP, e-commerce and marketplaces: a common language reduces errors and misunderstandings in multichannel projects.