1. The problem asks: What is a set? 2. A set is a fundamental concept in mathematics that refers to a collection of distinct objects, considered as an object in its own right. 3. These objects are called elements or members of the set. 4. Sets are usually denoted by curly braces, for example, $\{1, 2, 3\}$ is a set containing the elements 1, 2, and 3. 5. Important rules about sets: - Elements in a set are unique; duplicates are not counted. - The order of elements does not matter, so $\{1, 2\}$ is the same set as $\{2, 1\}$. 6. Sets can be finite or infinite, and they are used to group objects with common properties. Final answer: A set is a collection of distinct objects considered as a whole, denoted by curly braces, e.g., $\{a, b, c\}$.