What is Flexbox and what problem does it solve in CSS?

Explanation

Flexbox (Flexible Box Layout) is a one-dimensional layout model that provides an efficient way to arrange, align, and distribute space among items in a container, even when their size is unknown or dynamic. It handles horizontal or vertical layouts, spacing, alignment, and reordering. Flexbox solves common layout challenges like vertical centering, equal-height columns, and flexible spacing that were difficult with floats and positioning.