The Build-Measure-Learn (BML) cycle is a key component of the Lean Startup methodology, which aims to help startups and businesses quickly and effectively validate their business ideas and assumptions through experimentation and iteration.

The BML cycle consists of three phases:

1. Build: In this phase, you create a minimum viable product (MVP) that allows you to test your assumptions and hypotheses about your product or service. The goal is to create something that is good enough to test your ideas but not overly complex or time-consuming to build.
   
   
2. Measure: In this phase, you measure the impact of your MVP by collecting data and feedback from real users. This could involve gathering metrics such as user engagement, conversion rates, or customer satisfaction scores.
   
   
3. Learn: Based on the data and feedback collected in the Measure phase, you can learn and iterate on your product. You can refine your assumptions, adjust your product features or pricing, and identify new opportunities to improve and grow your business.
   

The BML cycle is iterative, meaning that you repeat the process over and over again, constantly refining and improving your product based on the feedback you receive. This approach allows you to quickly and efficiently build products that meet the needs of your customers and deliver value to your business.