Focus indicators are essential elements in web design that enhance accessibility by visually highlighting interactive components for users who navigate websites using keyboards instead of mice or touch devices. The article explains that these indicators, typically seen as a blue outline on elements like links, buttons, and form inputs, are crucial for individuals with disabilities, power users who prefer keyboard shortcuts, and those with temporary limitations. Customizing focus indicators to fit a website's design, while maintaining sufficient color contrast, ensures that users can easily identify focused elements. The text also discusses advanced CSS techniques, such as :focus-within and :focus-visible, which allow developers to refine focus styles for specific user interactions and improve user experience by differentiating between keyboard and mouse users. Additionally, it highlights the importance of maintaining a logical focus order when using CSS properties like flexbox and grid to rearrange elements, stressing the need for testing to ensure seamless navigation.