

First published in 2011, 'The Lean Startup' by Eric Ries introduces a scientific approach to creating and managing startups in an era of extreme uncertainty. Rather than following traditional business plans that require months of development before launch, Ries advocates for 'validated learning' through rapid experimentation and customer feedback. The book defines a startup as 'a human institution designed to create a new product or service under conditions of extreme uncertainty,' suggesting its principles apply to both garage-based entrepreneurs and large corporations (Wikipedia; Ries, 2011).
The fundamental feedback loop of a startup. The goal is to minimize the total time through the loop: turning ideas into products (Build), measuring customer response (Measure), and deciding whether to pivot or persevere (Learn) (theleanstartup.com).
A version of a new product that allows a team to collect the maximum amount of validated learning about customers with the least effort. It is not necessarily the smallest product, but the fastest way to test business hypotheses (leanstartup.co).
The process of demonstrating empirically that a team has discovered valuable truths about a startup's business prospects through scientific experimentation rather than vanity metrics (Wikipedia).
A way of evaluating progress by focusing on actionable metrics (which show cause and effect) rather than vanity metrics (which look good on paper but don't reflect health) to hold entrepreneurs accountable (hypeinnovation.com).
A structured decision point where a company decides whether to change its fundamental strategy (pivot) based on data or continue on its current path (persevere) (Medium).