The word "since" is often used to indicate a starting point in time. For example, you might say, "I have lived in New York since 2010." This means that your time in New York began in 2010 and continues to the present. It helps to show how long something has been happening. Additionally, "since" can also be used to explain a reason or cause. For instance, you might say, "I stayed home since it was raining." In this case, the rain is the reason for staying home. Using "since" helps to connect events and clarify relationships between them.