Every piece of writing has a main idea. Often, the main idea is expressed in the first sentence or first paragraph. The remainder of the text includes details and information that explain the main idea.

Supporting details are the facts, reasons, and examples that writers use to explain their main ideas. To identify supporting details, identify the main idea and then find facts or ideas in the text that back up or explain that idea. Statements that merely repeat the main idea or make a different point are not supporting details.