The phrase "what is" is a common English expression used to inquire about the definition, nature, or explanation of something. It is often the beginning of a question asking for clarification or understanding of a concept, object, or idea. If the question is about a specific topic starting with "what is," please provide the full phrase or topic for a specific and detailed answer. For example, "What is love?" can refer to the popular 1993 dance song "What Is Love" by Haddaway, which was a major hit in Europe and beyond. It can also be a profound philosophical or emotional question about the nature of love itself. Would there be a particular "what is" topic or phrase to explain or define?