Check out example codes for "flex parameters". It will help you in understanding the concepts better.

Code Example 1

flex: none | [ <'flex-grow'> <'flex-shrink'>? || <'flex-basis'> ]

Code Example 2

The flex CSS property sets how a flex item will grow or shrink to fit the space
available in its flex container. It is a shorthand for flex-grow , flex-shrink ,
and flex-basis .

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