eCommerce Engineering Glossary

Plain-English definitions of the terms you\'ll run into while working on Shopify, BigCommerce, Salesforce Commerce Cloud, NetSuite, and headless commerce projects. Written by engineers who actually ship on these platforms.

34 terms · last updated 2026-04-17

BigCommerce Multi-Storefront: A BigCommerce account feature that lets merchants run multiple storefronts off a shared catalogue, with per-channel pricing, inventory, and checkout.
BigCommerce Stencil: BigCommerce's theme framework. Handlebars templates plus a component-based JavaScript layer, with SCSS styling and a CLI for local development.
Checkout Extensions: UI extensions to Shopify's hosted checkout that run in an isolated iframe with Shopify APIs. The current supported way to customise checkout after checkout.liquid deprecation.
CLS (Cumulative Layout Shift): Sum of unexpected layout shifts during a page visit. Target: ≤ 0.1. Most commonly caused by images without explicit dimensions and fonts loaded without display: swap.
Composable Commerce: Extension of headless where multiple best-of-breed services (CMS, search, loyalty, etc.) are composed together with the commerce engine. Often uses MACH (Microservices, API-first, Cloud-native, Headless).
Content Security Policy (CSP): An HTTP response header that tells the browser which origins may load scripts, styles, images, frames, etc. Primary defence against Magecart-style XSS on eCommerce stores.
Core Web Vitals: Google's user-experience metrics used as ranking signals: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS).
E-E-A-T: Experience, Expertise, Authoritativeness, and Trustworthiness — the quality framework Google raters (and ranking systems) use to evaluate content, particularly in YMYL topics.
ERP: Enterprise Resource Planning — software that integrates core business processes (inventory, finance, procurement, HR). NetSuite, SAP, and Microsoft Dynamics are the dominant systems for mid-market and enterprise commerce.
European Accessibility Act (EAA): EU regulation requiring eCommerce sites selling to EU consumers to meet WCAG 2.1 AA accessibility standards. In force since 28 June 2025.
Generative Engine Optimization (GEO): Practices that improve a site's likelihood of being cited by generative AI search tools (ChatGPT, Claude, Perplexity). Overlaps with traditional SEO but emphasises structured content, clear answers, and machine-readable data.
Headless Commerce: Architecture where the storefront (frontend) is decoupled from the commerce platform (backend) and communicates via APIs. Enables custom UX at the cost of more engineering.
IndexNow: Protocol for instantly notifying search engines (Bing, Yandex, Seznam, Naver) that URLs have been added or updated. Host a key file at the domain root and POST JSON to api.indexnow.org.
INP (Interaction to Next Paint): The slowest interaction latency during a page visit. Replaced FID as a Core Web Vital in March 2024. Target: ≤ 200 ms.
LCP (Largest Contentful Paint): Time from navigation start until the largest visible element finishes rendering. Target: ≤ 2.5 seconds at the 75th percentile of real users.
llms.txt: A plain-text file at the root of a site that summarises the site's purpose and structure for LLM crawlers. Proposed standard for AI-readable site navigation.
NetSuite SuiteCommerce: Oracle NetSuite's commerce module. Tightly coupled to NetSuite ERP — orders, inventory, customers, and financials share a single data model with no integration middleware.
OCAPI: Open Commerce API — Salesforce Commerce Cloud's older REST API. Being replaced by the newer SCAPI for most use cases.
PCI DSS: Payment Card Industry Data Security Standard. Required for any merchant handling card payments. Version 4.0 came into full effect in March 2025.
Salesforce Commerce Cloud (SFCC): Enterprise eCommerce platform from Salesforce. Runs on the SFRA reference architecture with custom cartridges, OCAPI, and SCAPI integrations.
SCAPI: Salesforce Commerce API — the newer, OpenAPI-described replacement for OCAPI with improved performance and consistency.
SFRA: Storefront Reference Architecture — the modern template and controller architecture for Salesforce Commerce Cloud storefronts, replacing the legacy SiteGenesis.
Shopify Admin API: GraphQL and REST API for managing merchants' back-office data — products, orders, customers, inventory, fulfilment. Used by apps and integrations.
Shopify Flow: Shopify Plus's native workflow automation engine. Triggers on orders, customers, inventory, and products; supports conditions and multi-step actions.
Shopify Functions: Small WebAssembly modules that run inside Shopify's checkout, discount, cart-transform, delivery, and payment systems. Replace Shopify Scripts for new Plus merchants.
Shopify Hydrogen: Shopify's React-based framework for building custom storefronts on a headless Shopify backend. Built on Remix, deploys to Oxygen or Vercel.
Shopify Markets: Shopify's built-in internationalisation layer — multi-currency, translated storefronts, region-specific pricing and domain routing from a single store.
Shopify Oxygen: Shopify's managed edge hosting platform for Hydrogen storefronts. Co-located with Shopify infrastructure for lowest-latency Storefront API calls.
Shopify Plus: Shopify's enterprise tier. Adds checkout customisation (Scripts, Functions, Checkout Extensions), B2B features with company accounts and price lists, Shopify Markets multi-currency, Shopify Flow automation, higher API rate limits, and up to nine expansion stores.
Shopify Storefront API: GraphQL API for reading products, collections, cart, and checkout data from Shopify. Used by headless storefronts including Hydrogen.
Structured Data (JSON-LD): Machine-readable metadata embedded in pages using schema.org vocabulary. Powers Google rich results and AI search engine citations.
SuiteScript: NetSuite's server-side scripting language (JavaScript variant) used to customise business logic, integrations, and UI behaviour across the platform.
SuiteTalk: NetSuite's SOAP and REST web services layer for external integrations. Used by most Shopify/BigCommerce ↔ NetSuite sync pipelines.
Webhooks: HTTP callbacks fired by commerce platforms when events happen (orders/create, inventory/update, etc.). Essential for real-time sync between platforms.

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