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.
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.
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.
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.
self-hosting: Running software on infrastructure you control rather than renting a managed service. Cheaper for steady load, and your data stays yours.