How does CSS specificity work?

CSS specificity is a crucial aspect of how styles are applied to elements in HTML. It determines which rules take precedence when multiple CSS styles apply to the same element. Specificity is calculated based on the types of selectors used: inline styles have the highest specificity, followed by IDs, then classes, attributes, and pseudo-classes, and finally, tag names or elements have the lowest specificity.

For instance, if you have a style defined for a class and another style defined for an ID that both apply to the same element, the ID selector will override the class selector due to its higher specificity ranking. This allows for fine-tuning of styles and helps prevent conflicts between different styles that might be applied in various stylesheets.

In the context of the other options, the first option regarding loading CSS files is related to the order in which stylesheets are included in the HTML but does not directly deal with specificity. The second option about the order of scripts pertains to JavaScript and has no relevance to CSS specificity. Lastly, while certain optimizations can improve loading speed, specificity itself does not play a role in that aspect; it strictly relates to how styles are applied to the elements presented on the page.