What is essential for maintaining a theme's visual representation across various devices?

Implementing the Bootstrap grid system or media queries is essential for maintaining a theme's visual representation across various devices because these tools allow for responsive design. Responsive design is crucial in ensuring that the layout adapts to different screen sizes, such as mobile, tablet, and desktop.

The Bootstrap grid system provides a framework that uses a series of containers, rows, and columns to structure content. This grid system adjusts the elements on the page depending on the size of the screen, ensuring a cohesive and visually appealing layout, regardless of the device being used.

Similarly, media queries are a CSS technique that allows developers to apply different styles based on the device's characteristics, such as width and height. By defining specific styles for different breakpoints, it is possible to control how elements appear and behave on various screens, further enhancing user experience.

In contrasting this with other options, a consistent HTML structure is important for overall organization and semantic clarity, but it does not inherently address visual adaptability. Creating resolutions for each device type can lead to excessive work and is not practical due to the vast array of devices available. Relying solely on JavaScript for functionality does not contribute to visual representation; it primarily focuses on interactivity and dynamic content processing. Thus, the combination of