Plain-English glossary.
A practical reference for software builders, indie founders, and early-stage teams.
- API
- An interface that lets software systems request data or actions from one another using defined rules.
- ARR (Annual Recurring Revenue)
- The annualized value of recurring subscription revenue. It is a run-rate metric, not necessarily cash collected in a year.
- Churn
- The rate at which customers or recurring revenue are lost during a period. State whether a metric measures customer churn or revenue churn.
- CI/CD
- Continuous integration and continuous delivery/deployment: automated checks and processes that help teams ship software safely and frequently.
- Customer discovery
- Research to understand a target customer's problems, current workarounds, buying context, and desired outcomes before committing to a solution.
- DAU / MAU
- Daily active users and monthly active users. Define "active" around meaningful product behavior rather than logins alone.
- Deployment
- Making a software version available in an environment. Deployment does not automatically mean every user can access it.
- Docker container
- An isolated process packaged with the dependencies it needs, built from an image and run by a container runtime.
- ICP (Ideal Customer Profile)
- A description of the organizations or people most likely to benefit from and buy a product.
- LLM (Large Language Model)
- A model trained to process and generate language. It can produce plausible errors, so important outputs need validation.
- MVP (Minimum Viable Product)
- The smallest useful version or experiment that can test a critical product assumption with real users.
- MRR (Monthly Recurring Revenue)
- The normalized monthly value of active recurring subscriptions, excluding one-off revenue unless explicitly defined otherwise.
- Product-market fit
- A condition where a defined market repeatedly chooses and retains a product because it solves an important problem. It is evidenced by behavior, not a single launch spike.
- Retention
- The share of users or customers who continue to return or pay over a defined period.
- SaaS
- Software as a Service: software delivered as an ongoing service, commonly through a subscription.
- SQL (Sales Qualified Lead)
- A prospect assessed as ready for a sales conversation. In developer contexts, SQL also means Structured Query Language; use context to disambiguate.
- Unit economics
- Revenue and costs associated with one unit of a business, such as one customer, transaction, or subscription account.
- Webhook
- An HTTP request one system sends to another when a specified event occurs.
Definitions are concise starting points; accounting, security, and architecture terms can vary by context.