Plain-English definitions

Glossary

Short, practical definitions of the software and business terms small teams run into. Written without jargon, updated when the meaning shifts.

API: An API (application programming interface) is a set of rules that lets two pieces of software exchange data or commands automatically, without a human in the middle.
Caching: Caching is storing a copy of data or a computed result so future requests are served instantly instead of recomputed or refetched — the most common way to make software faster.
CDN (content delivery network): A CDN is a global network of servers that caches copies of your site near your users, cutting latency and load so pages load faster and your origin server does less work.
Churn / retention: Churn measures how many customers or how much recurring revenue you lose in a period. Retention measures the opposite — how many customers stay active or renew.
Core Web Vitals: Core Web Vitals are Google's three user-experience metrics — LCP (loading), INP (responsiveness) and CLS (visual stability) — measured on real visitors and used as a ranking signal.
CRM: A CRM (customer relationship management tool) is software that keeps contacts, conversations and deals in one place so nothing gets lost as your client list grows.
Kanban: Kanban is a visual method for managing work using columns (stages) and cards (work items), with an explicit limit on how many items are in progress at the same time.
Lead scoring: Lead scoring is the practice of assigning a numeric value to every lead based on demographics and behavior, so sales and marketing can prioritize follow-up on the people most likely to buy.
LLM (large language model): An LLM is an AI model trained on massive text data to predict the next token, letting it generate and understand language — powering tools like ChatGPT, Claude and coding assistants.
MRR / ARR: MRR (monthly recurring revenue) is the predictable income your subscription business earns each month. ARR (annual recurring revenue) is the same number multiplied by 12 — the annualized view.
Project management tool: A project management tool is software that keeps tasks, owners, deadlines and status in one place so a team can see what is happening without asking.
Prompt engineering: Prompt engineering is the practice of writing clear, structured instructions for an AI model so it produces useful, reliable output — through context, examples, constraints and iteration.
RAG (retrieval-augmented generation): RAG is a pattern where an AI first retrieves relevant text from your own documents, then uses it to generate an answer — reducing hallucinations and letting an LLM work with private, current data.
SaaS: SaaS (software as a service) is cloud-hosted software you access through a browser and pay for with a recurring subscription, usually per user per month.
Workflow automation: Workflow automation is software that triggers actions automatically in response to events — like 'new form submission creates a task' — so small teams skip repetitive manual work.