CSS Flexbox and Grid Layout Explained

Flexbox and Grid are both modern CSS layout systems but serve different purposes. Flexbox is one-dimensional — it excels at distributing space along a single axis (either a row or a column). It's ideal for navigation bars, card rows, centering content, and aligning items within a container. Key properties include flex-direction to set the axis, justify-content for main-axis alignment, align-items for cross-axis alignment, and flex-grow/shrink/basis to control how items share space. flex-wrap allows items to wrap onto new lines. Grid is two-dimensional — it manages both rows and columns simultaneously, making it perfect for page layouts, dashboards, and complex grid structures. You define the grid structure explicitly with grid-template-columns and grid-template-rows, using units like fr (fractional unit) for flexible sizing, repeat() for repetitive patterns, and minmax() for responsive bounds. Grid also supports named grid areas for semantic layout. The key mental model: Flexbox is content-driven (the content's size influences the layout), while Grid is layout-driven (you define the grid first, then place items into it). In practice, they work great together — use Grid for the overall page structure and Flexbox for individual component layouts within grid cells. For responsive design, Grid's auto-fill/auto-fit with minmax() creates fluid grids without media queries.