Final answer:
An assumption is a belief or statement accepted as true without evidence, serving as a critical starting point for reasoning or theories, but requires careful assessment to ensure they do not lead to incorrect conclusions.
Step-by-step explanation:
An assumption is something that is accepted as true or as certain to happen, without proof. It is a belief or statement taken for granted without evidence. In various fields, assumptions are foundational to arguments, theories, and hypotheses. They provide a starting point for reasoning or calculation, but it is important to evaluate them critically since faulty assumptions can lead to incorrect conclusions.
In everyday life, assumptions can influence how we think and act. For example, if you assume it will rain, you might carry an umbrella. In more formal settings such as scientific research, a researcher might make an assumption about the behavior of a natural system that allows them to create a model or conduct an experiment.