A more thorough explanation:

Definition: In the context of patents, an invention must be both new and useful to be patentable. Novelty means that the invention is not already known or publicly disclosed, while usefulness means that the invention has some practical application or benefit.

Example: A new type of smartphone that has a longer battery life and a faster processor would be considered new and useful, and therefore eligible for a patent. On the other hand, an idea for a perpetual motion machine that violates the laws of physics would not be considered useful and would not be patentable.

Explanation: The example of the smartphone illustrates an invention that is both new and useful, as it offers practical benefits to consumers. In contrast, the perpetual motion machine example is not useful because it cannot actually be built or used to perform any useful function. Therefore, it would not meet the requirements for patentability.