A scientific investigation is a search to use the scientific method to find an answer to a question. On the other hand, the scientific method is a systematic procedure that involves formulating, testing, or modifying a hypothesis using measurable observations. Finally, an idea is a proposed explanation based on experience or research for some observed phenomenon. People like you and me employ scientific study to generate better models and answers for the world around us.
Science is built on the foundation of investigation. It's how scientists conduct their research. Scientific research yields evidence that can be used to answer questions and solve issues. Even if the evidence is unable to provide answers or solutions, it may be valuable. It could raise new problems or difficulties that need to be investigated.