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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