Because is a conjunction. It typically expresses a logical link between two ideas or events. Often, this link is due to cause and effect.
When to Use Since
Since is also a conjunction that expresses a logical link between two ideas or events. In this way, it can sometimes be a synonym of because.
Is it because or since? Because and since are conjunctions that describe a logical relationship between ideas or events. Since can also describe a sequential relationship between two events. Since can be ambiguous, so use it carefully.