Page Object Model gem for ruby Page Objects are like react-components for integration spec code. They let you componentize pages or parts of pages so you don't use css-selectors every where.
If you have page.find('button', text: 'update section') in a lot of tests, when the PM says it should be 'Change Section' you have a lot of changes to make. By sticking this in the page-object it limits the needed scope of change to just that POM and possible the one test that regression checked this.
Let you define elements on your page