Integrations fail at the boundaries: one system sends a request, another validates it, limits its rate, returns data or reports an error. The labels here cover transport styles, credentials, retries and data movement. A successful HTTP response does not necessarily mean the business operation succeeded, and a retry can repeat a charge unless the operation is designed to be safe.
🧭 Jump to a term
Make and receive API requests: Application programming interface (API) · Representational State Transfer (REST) · GraphQL (graph query language) · Webhook · API endpoint · Payload
Control access and request volume: Authentication · OAuth (Open Authorization) · API key · Rate limit · Pagination
Make operations reliable and move data: Idempotency · Exponential backoff · Extract, transform, load (ETL) · Extract, load, transform (ELT) · Electronic data interchange (EDI) · Integration platform as a service (iPaaS) · API versioning
⭐ Know these first
Start with Application programming interface (API), Webhook, OAuth (Open Authorization), Rate limit, Idempotency. Then follow the grouped learning order below.
📎 How to read this page
What it means gives the precise meaning. Operator translation gives the version you might hear in a real ecommerce meeting. In real life shows an illustrative example. Watch out and the confusion boxes show where a familiar term can mislead.
📈 Read the relationships first
These combinations are diagnostic hypotheses, not proof of causality. Compare the same period and scope, then investigate the mechanism.
Timeouts ↑ + duplicate operations ↑
Usually means: the client may retry requests whose outcome is uncertain. Check next: idempotency support and operation logs.
Request volume ↑ + 429 responses ↑
Usually means: the integration is exceeding a provider limit. Check next: quota scope, pagination and backoff behavior.
Schema changes ↑ + downstream failures ↑
Usually means: consumers may depend on removed or reinterpreted fields. Check next: versioning, contract tests and deprecation notices.
Make and receive API requests
01 · 🟢 Core
Application programming interface (API) = Contract for software interaction
🧠 What it means
A defined interface through which one software system can request data or actions from another using documented operations and rules.
💬 OPERATOR TRANSLATION
“An API is a contract; confirm the endpoint, authentication, schema and behavior.”
🛍️ In real life
A storefront requests current inventory from a warehouse system through its API.
🔗 Related: Representational State Transfer (REST) · GraphQL (graph query language) · Webhook · ↑ all terms
02 · 🔵 Operations
Representational State Transfer (REST) = Architectural style for networked APIs
🧠 What it means
An architectural style that organizes interactions around resources and standard web semantics, commonly using HTTP methods and status codes.
💬 OPERATOR TRANSLATION
“REST is a style with constraints, not a synonym for any JSON endpoint.”
🛍️ In real life
A client retrieves an order resource with GET and submits an update with an appropriate method.
🔗 Related: Application programming interface (API) · GraphQL (graph query language) · Webhook · ↑ all terms
03 · 🔵 Operations
GraphQL (graph query language) = Query language and runtime for APIs
🧠 What it means
A query language and server-side runtime that lets a client request a defined data shape from a GraphQL service.
💬 OPERATOR TRANSLATION
“Ask for the fields the screen needs; schema and resolver behavior still matter.”
🛍️ In real life
A product page requests name, price and availability in one GraphQL query.
🔗 Related: Application programming interface (API) · Representational State Transfer (REST) · Webhook · ↑ all terms
04 · 🟢 Core
Webhook = Event notification sent to a URL
🧠 What it means
A mechanism where one system sends an HTTP request to another when a configured event occurs. Delivery, retries and signature validation are implementation-specific.
💬 OPERATOR TRANSLATION
“Assume delivery can be delayed or repeated; validate and deduplicate events.”
🛍️ In real life
A payment service sends an order-paid event to the merchant’s webhook endpoint.
🔗 Related: Application programming interface (API) · Representational State Transfer (REST) · GraphQL (graph query language) · ↑ all terms
05 · 🔵 Operations
API endpoint = Address for a specific API operation
🧠 What it means
A network address and method combination through which a client accesses a particular API resource or action.
💬 OPERATOR TRANSLATION
“The URL is only part of the contract; method, parameters and permissions matter too.”
🛍️ In real life
A client calls the documented inventory endpoint for a specific SKU.
🔗 Related: Application programming interface (API) · Representational State Transfer (REST) · GraphQL (graph query language) · ↑ all terms
06 · 🔵 Operations
Payload = Data carried in a request or response
🧠 What it means
The body or structured data transmitted as part of a message, such as an API request, response or webhook event.
💬 OPERATOR TRANSLATION
“Validate the payload shape and meaning before changing business records.”
🛍️ In real life
An order-created payload contains an order ID, line items and currency.
🔗 Related: Application programming interface (API) · Representational State Transfer (REST) · GraphQL (graph query language) · ↑ all terms
Control access and request volume
07 · 🔵 Operations
Authentication = Verification of identity or credential
🧠 What it means
A process by which a system verifies a user, client or service before granting access. It is distinct from authorization, which determines permitted actions.
💬 OPERATOR TRANSLATION
“First prove who is calling; then check what that caller may do.”
🛍️ In real life
An integration presents a valid credential before reading order data.
🔗 Related: OAuth (Open Authorization) · API key · Rate limit · ↑ all terms
08 · 🟢 Core
OAuth (Open Authorization) = Delegated authorization framework
🧠 What it means
A framework that lets a client obtain limited access to a resource on behalf of a user or service, using grants and tokens. OAuth is authorization plumbing, not a user login protocol by itself.
💬 OPERATOR TRANSLATION
“Request the minimum scopes and handle token expiry and revocation.”
🛍️ In real life
A store owner grants an app read-only access to product data.
🔗 Related: Authentication · API key · Rate limit · ↑ all terms
09 · 🔵 Operations
API key = Secret identifying an API client
🧠 What it means
A token-like value an API provider issues to identify or control access for a client, often with restrictions or quotas.
💬 OPERATOR TRANSLATION
“Treat the key as a secret; do not ship privileged keys in public browser code.”
🛍️ In real life
A server stores its reporting API key in a secret manager and rotates it when needed.
🔗 Related: Authentication · OAuth (Open Authorization) · Rate limit · ↑ all terms
10 · 🟢 Core
Rate limit = Cap on request volume
🧠 What it means
A provider-enforced limit on how many API requests a client can make in a period or under a specific policy.
💬 OPERATOR TRANSLATION
“Read the provider’s limit headers and slow down when instructed.”
🛍️ In real life
An integration pauses after a 429 response and resumes within the documented quota.
🔗 Related: Authentication · OAuth (Open Authorization) · API key · ↑ all terms
11 · 🔵 Operations
Pagination = Method for retrieving results in chunks
🧠 What it means
A way to split a large result set into pages using offsets, cursors, tokens or links.
💬 OPERATOR TRANSLATION
“Keep requesting pages until the API says the result set is complete.”
🛍️ In real life
A reconciliation job follows a next-page cursor to fetch every order.
🔗 Related: Authentication · OAuth (Open Authorization) · API key · ↑ all terms
Make operations reliable and move data
12 · 🟢 Core
Idempotency = Same operation can be retried safely
🧠 What it means
A property that makes repeated requests with the same key or operation identity produce one logical effect rather than duplicates.
💬 OPERATOR TRANSLATION
“Use the same idempotency key when retrying an uncertain create or charge request.”
🛍️ In real life
A checkout retry with the original key returns the first charge result instead of creating another charge.
🔗 Related: Exponential backoff · Extract, transform, load (ETL) · Extract, load, transform (ELT) · ↑ all terms
13 · 🔵 Operations
Exponential backoff = Retry delay that grows after failures
🧠 What it means
A retry strategy that increases the wait between attempts, often with a cap and random jitter, to reduce load during transient failure.
💬 OPERATOR TRANSLATION
“Retry transient errors patiently; do not retry permanent validation errors.”
🛍️ In real life
A worker waits longer after each temporary 503 response and stops at its configured attempt limit.
🔗 Related: Idempotency · Extract, transform, load (ETL) · Extract, load, transform (ELT) · ↑ all terms
14 · 🔵 Operations
Extract, transform, load (ETL) = Transform data before loading
🧠 What it means
A data pipeline pattern that extracts source data, transforms it in a processing layer and loads the result into a destination.
💬 OPERATOR TRANSLATION
“Clean and reshape the data before it reaches the target system.”
🛍️ In real life
A nightly job maps order fields to a warehouse schema before loading them.
🔗 Related: Idempotency · Exponential backoff · Extract, load, transform (ELT) · ↑ all terms
15 · 🔵 Operations
Extract, load, transform (ELT) = Load data before transforming it
🧠 What it means
A data pipeline pattern that extracts data, loads it into a target platform and performs transformations there.
💬 OPERATOR TRANSLATION
“Land source data first, then use the destination’s compute to transform it.”
🛍️ In real life
An analytics team loads raw event tables and runs SQL models in its warehouse.
🔗 Related: Idempotency · Exponential backoff · Extract, transform, load (ETL) · ↑ all terms
16 · 🔵 Operations
Electronic data interchange (EDI) = Structured business document exchange
🧠 What it means
A standards-based exchange of structured business documents between organizations, often for orders, invoices or shipment notices.
💬 OPERATOR TRANSLATION
“Agree the document standard, partner mapping and acknowledgement behavior.”
🛍️ In real life
A retailer sends a purchase order and receives an EDI invoice from a supplier.
🔗 Related: Idempotency · Exponential backoff · Extract, transform, load (ETL) · ↑ all terms
17 · 🔵 Operations
Integration platform as a service (iPaaS) = Managed integration tooling
🧠 What it means
A cloud service that helps build, run and monitor integrations between applications, often with connectors and workflow tools.
💬 OPERATOR TRANSLATION
“A connector accelerates setup; map ownership, error handling and costs too.”
🛍️ In real life
An iPaaS workflow syncs new orders to a fulfillment provider and logs failures.
🔗 Related: Idempotency · Exponential backoff · Extract, transform, load (ETL) · ↑ all terms
18 · 🔵 Operations
API versioning = Managing contract changes over time
🧠 What it means
A method for evolving an API while communicating compatibility boundaries and allowing clients to migrate safely.
💬 OPERATOR TRANSLATION
“Version breaking changes deliberately and publish a deprecation path.”
🛍️ In real life
A client upgrades from v1 to v2 after checking field changes and sunset dates.
🔗 Related: Idempotency · Exponential backoff · Extract, transform, load (ETL) · ↑ all terms
🔀 Authentication vs authorization
Authentication verifies identity. Authorization determines which operations that identity may perform.
🔀 REST vs GraphQL
REST commonly exposes resource-oriented operations; GraphQL lets a client query a schema-defined data shape.
🔀 ETL vs ELT
ETL transforms before loading. ELT loads first and transforms in the destination.
🔀 Webhook vs polling
A webhook pushes an event notification. Polling repeatedly asks whether something changed.
🤔 Still confused?
Follow this thread: Application programming interface (API) → Authentication → Idempotency. That sequence moves from the basic object or relationship to the decisions and checks it supports.
Sources and scope
Primary documentation checked on 27 September 2026. Platform features and eligibility can change; examples and cartoon situations are illustrative.
