An iteration is a timebox during which development takes place. The duration may vary from project to project and is usually fixed.| Agile Alliance |
A user story helps agile software development teams capture a simple, high-level description of user requirements, written from the user perspective. For agile software development, writing good user stories is essential. Here's why.| Easy Agile
The Pareto Principle specifies that 80% of consequences come from 20% of the causes, asserting an unequal relationship between inputs and outputs.| Investopedia
As a member of the Scrum Team, the Product Owner provides clarity to the team about a product’s vision and goal. All work is derived and prioritized based on the Product Goal in order to deliver value to all stakeholders including those within their organization and all users both inside and out.| Scrum.org
The Scrum Master is accountable for establishing Scrum. They do this by helping everyone understand Scrum theory and practice, both within the Scrum Team and the organization while serving the Scrum Team as well as the larger organization.| Scrum.org