Glossary.

Every technical term this site uses, defined in a sentence or two. Written for someone who makes buying decisions, not for someone who already knows.

3-D Secure: The bank verification step in an online card payment, usually a one-time code. It proves the cardholder is who they say they are.
API: A defined interface that lets two pieces of software talk to each other. A checkout page might call one to pull pricing from a payment provider or push a new customer into a CRM.
API rate limit: A cap on how many requests an API accepts in a given window. Once a client crosses it, requests get rejected until the window resets, which is why busy automations need retry and queueing built in.
CI/CD: An automated pipeline that tests every change and ships it safely. No manual steps, so releasing often stops being risky.
containers: An app packaged with everything it needs to run. It behaves the same on a laptop, a build server, and production.
Core Web Vitals: Google's three headline measures of how a page feels: how fast the main content appears, how quickly it responds, and whether the layout jumps.
deployment: Moving an application, or a new version of one, into the environment where it actually runs. It can be a manual step or something a CI/CD pipeline does on its own.
device firmware: The low-level software that runs directly on a piece of hardware, controlling how its sensors and other components behave. Updating it in the field is what an OTA pipeline exists for.
GEO: Generative Engine Optimization. Structuring a page so ChatGPT, Perplexity, and Gemini can read it, trust it, and quote it in an answer.
HMAC-SHA512: A cryptographic signature over a payment message. It proves nothing was altered in transit, and it only matches if both sides built the message identically.
human review: Routing a decision to a person when an automated or AI system is not confident enough to make it alone. Safer than letting the system guess at something it genuinely does not know.
idempotency: Designing an operation so running it twice does the same thing as running it once. It is what makes a retry safe in payments.
infrastructure as code: Servers and infrastructure defined in version-controlled files. Environments become reproducible, reviewable, and quick to rebuild.
Interaction to Next Paint: Interaction to Next Paint. How long a page takes to visibly respond after a tap or a click.
JSON-LD: A structured description of what a page means, written for machines. It is how search and AI engines know what they are looking at.
LLM: Large Language Model. The kind of AI that reads and writes text. Useful for extraction, but it proposes rather than decides.
MQTT: A lightweight messaging protocol built for sensors and devices. It copes with low bandwidth and connections that drop.
n8n: A workflow tool that connects your systems and runs multi-step jobs on its own. Self-hosted, so your records never reach a third-party vendor.
observability: Logs, metrics, and alerts that show what a live system is actually doing. It is how you find a problem before your users report it.
OTA updates: Over-the-air updates. Device firmware patched remotely, in stages, with a way back, so nobody has to drive out to each unit.
production: The live system real users and real operations run on, as opposed to development or staging. A bug here touches real people, real data, and real money.
PWA: Progressive Web App. A web app built to behave like a native one: installable, works offline to a degree, and can reach some device features, within whatever the platform allows.
retry: Re-running a failed operation under a defined set of rules, usually after a timeout or a transient service error. Left uncontrolled it produces duplicates, so anything that touches money or orders pairs it with idempotency.
rollback: Reverting a system to the last working release after a deployment or update goes wrong. A safe rollback path is what keeps a bad release contained instead of becoming an incident.
schema: The set of rules a system uses to accept data: which fields exist, what type each one is, and which values are valid. It is how you check that a model's or a service's output matches the shape you actually need.
self-hosting: Running software on infrastructure you control rather than renting a managed service. Cheaper for steady load, and your data stays yours.
source of truth: The one place in a system that is trusted to be correct when other records disagree. If order status lives in the ERP, that is the source of truth, not whatever a dashboard cached an hour ago.
telemetry: The measurements a device or system reports about its own state. On an IoT fleet that is things like temperature, battery level, connection status, and when it last checked in.
webhook: An HTTP request a system fires automatically when something happens on its end. A payment provider, for instance, can hit your backend the moment a charge succeeds.