What does a Registered Trademark protect?

A Registered Trademark primarily protects the distinctiveness of a brand by signifying that a particular word, phrase, symbol, or design identifies and distinguishes the source of goods or services. This protection extends to the expression of ideas rather than the ideas themselves. Thus, the trademark ensures that consumers can reliably identify the origin of a product, which ultimately safeguards the brand's reputation.

The focus on the looks of the design highlights that trademarks, especially logos or brand symbols, are legally protected from being copied or imitated by others. This fosters brand identity and helps consumers avoid confusion in the marketplace.

In contrast, the other options touch on different aspects of intellectual property that are covered by different types of protections. For instance, the reputation of a company relates more closely to branding and might be protected indirectly by trademark laws, but is not the sole protective effect of a trademark. The function and usability of a product would fall under patent protection, while the originality of the idea is typically safeguarded by copyright laws, not trademarks.