Plain-English definitions of the terms product documents are built from — each one self-contained, with a concrete product example and links into the document library.
A/B testing is a controlled experiment that compares two versions of a product experience by randomly splitting users between them and measuring which performs better against a defined metric.
Acceptance criteria are the specific, testable conditions a piece of work must satisfy before it is considered done.
Activation rate is the percentage of new users who reach the moment where they first experience a product's core value — completing the setup or action that predicts they will keep using it.
Assumption mapping is a discovery technique that surfaces the beliefs an idea depends on and plots them by how important and how uncertain they are.
A business case is a structured argument for whether to invest in a product initiative.
Churn rate is the percentage of customers or revenue lost over a given period — those who cancel, stop paying or stop using the product.
Cohort analysis is a technique that groups users by a shared characteristic, usually the time they first signed up, and tracks how each group behaves over its lifetime.
A competitive analysis is a structured comparison of the alternatives customers can choose instead of your product, including direct rivals, indirect substitutes and doing nothing.
Customer acquisition cost (CAC) is the average total cost of winning a new customer, calculated by dividing all sales and marketing spend over a period by the number of customers acquired in it.
Customer lifetime value (LTV or CLV) is the total profit a business expects to earn from a customer over the entire relationship.
A customer problem statement is a concise, evidence-based description of a specific problem a defined group of users experiences, in their context and words.
A decision-grade document is one a stakeholder can act on without re-checking the work: every material claim traces to a source or is flagged as an assumption, each section is sized to the decision it serves, the evidence behind conclusions is visible, and a named reviewer has signed it off..
The Definition of Done is a shared, agreed checklist of the quality criteria a piece of work must meet before it can be considered complete.
Dual-track agile is a way of working that runs two continuous, parallel tracks: discovery, which validates what is worth building, and delivery, which builds and ships it.
An epic is a large body of work in an agile backlog — too big to deliver in one go — that is broken down into smaller user stories.
Feature creep is the gradual, unplanned accumulation of features beyond a product's original scope — each addition individually reasonable, but collectively bloating the product, diluting its focus and increasing complexity for users and maintainers.
A feature flag (or feature toggle) is a mechanism that lets teams turn functionality on or off in production without deploying new code.
A go-to-market (GTM) strategy is the plan for how a product will reach and win its customers.
Jobs-to-be-Done (JTBD) is a framework for understanding demand by focusing on the progress a customer is trying to make — the 'job' they 'hire' a product to do — rather than their demographics or the product's features.
The Kano model is a framework for prioritising product features by how they affect customer satisfaction.
A KPI (key performance indicator) is a quantifiable measure used to track how well a product, team or business is performing against its goals.
A market research report is a structured summary of what a team has learned about a market: its size and growth, customer segments and needs, competitors, trends and risks.
A minimum viable product (MVP) is the smallest version of a product that can be released to real users to test whether the core idea works.
MoSCoW prioritisation is a technique that sorts requirements into four categories: Must have, Should have, Could have and Won't have (this time).
Non-functional requirements (NFRs) specify how a system should perform rather than what it should do.
A North Star Metric is the single measure that best captures the core value a product delivers to its customers.
OKR (Objectives and Key Results) is a goal-setting framework that pairs a qualitative objective — what you want to achieve and why it matters — with three to five measurable key results that show whether you achieved it.
An opportunity assessment is a short, structured evaluation of a product idea before committing to build it.
A product backlog is the single, ordered list of everything that might be delivered for a product: features, fixes, improvements and technical work.
Product discovery is the work of understanding a problem space before committing to build: who the users are, which problems are worth solving, and which opportunities justify investment.
The product lifecycle is the sequence of stages a product moves through — from initial discovery and validation, through planning, definition and build, to launch, optimisation and eventually scale or sunset.
A product pivot is a deliberate, structured change in product strategy — a new target customer, problem, business model or core offering — made when evidence shows the current direction will not reach product-market fit.
A Product Requirements Document (PRD) is a single reference that describes what a product or feature must do, for whom, and why.
A product roadmap is a communication tool that shows the direction a product will take over time and the outcomes it aims to achieve.
A product strategy is the plan for how a product will achieve its vision.
A product sunset is the planned retirement of a product or feature: deciding it no longer earns its place, then winding it down deliberately — notifying and migrating customers, honouring commitments, decommissioning systems and capturing lessons.
Product validation is the process of testing whether a product idea holds up against real evidence before significant resources are committed — evidence of demand, willingness to pay, technical feasibility and business viability.
A product vision describes the future a team is trying to create, typically two to five years out.
Product-market fit is the point at which a product satisfies strong demand in a viable market: customers actively adopt it, keep using it and recommend it, and growth starts to pull rather than needing to be pushed.
Retention rate is the percentage of users or customers who continue using a product over a given period.
RICE scoring is a prioritisation method that ranks initiatives using four factors: Reach (how many people are affected in a period), Impact (how much each is affected), Confidence (how sure you are of those estimates) and Effort (the work required).
Stakeholder alignment is the state in which the people who influence or depend on a product decision share the same understanding of the goal, the evidence and the trade-offs — and have visibly agreed to the direction.
Story points are a relative unit teams use to estimate the effort required to complete a piece of work, rather than measuring it in hours or days.
Technical debt is the accumulated cost of past shortcuts in how software was built — quick fixes, outdated dependencies, skipped refactoring — that makes future change slower and riskier.
Time to value (TTV) is how long it takes a new user to reach the first meaningful benefit from a product after signing up.
Total Addressable Market (TAM) is the total revenue opportunity available if a product achieved complete market share of everyone who could conceivably buy it.
A user journey map is a visualisation of the steps a person takes to accomplish a goal with a product or service, along with their thoughts, emotions and pain points at each stage.
A user persona is a composite profile of a target user type, built from research rather than assumption.
A user story is a short description of a piece of functionality told from the user's perspective, typically in the form 'As a [user], I want [capability], so that [benefit]'.
A value proposition is a clear statement of the benefit a product delivers to a specific customer, the problem it solves and why it is better than the alternatives.