HTML and CSS Certification Practice Test

The 'flex' property in CSS Flexbox is a powerful tool that enables flexible layouts by allowing a flex item to grow or shrink according to the available space in its container. This property is essential for creating responsive designs, as it helps items maintain proportional sizes and adjust dynamically based on the size of the viewport or the containing element.

When you set the 'flex' property on a flex item, it effectively combines three properties: flex-grow, flex-shrink, and flex-basis. The flex-grow value determines how much of the available space the item should take up in relation to other flex items, while the flex-shrink value dictates how much the item should shrink if there isn’t enough space. The flex-basis defines the initial size of the item before any growing or shrinking takes place.

This flexibility ensures that your layout can adjust gracefully to varying screen sizes, making the 'flex' property crucial for modern web design and ensuring a smooth user experience across devices.