# CSS Responsiveness:
Responsive web design is an approach to designing and coding websites so that they provide an optimal viewing and interaction experience across a wide range of devices, from desktop computers to mobile phones. CSS plays a crucial role in achieving responsiveness.
Here are some key concepts related to CSS responsiveness:
## Fluid Grids
1. Use relative units like percentages instead of fixed units like pixels for widths and heights.
1. This allows elements to resize