A causal relationship refers to a connection between two events or variables where one directly influences or causes a change in the other. For example, if rain causes the ground to become wet, we can say there is a causal relationship between rain and the wet ground. This relationship helps us understand how different factors interact in various situations. In scientific research, establishing a causal relationship often requires controlled experiments or observational studies. Researchers look for patterns and use statistical methods to determine if changes in one variable, like temperature, lead to changes in another variable, such as ice melting. Understanding these relationships is crucial for making predictions and informed decisions.