The term “topic” is interchangeable with the term “subject.” The topic is the overall, broad theme of the work. The main idea, on the other hand, is the concept that’s being discussed in detail within the work. The main idea is narrower than the topic. Supporting details hash out the main idea. For example, the topic of a paper may be “child care,” but the main idea would be something more detailed, such as “caring for children ages 5 to 7.”
Each written work should have a main sentence that clarifies the main idea. This sentence condenses the details of the overall work into an all-inclusive statement that sets forth the work’s main idea. This is a way for the author to communicate with the audience the main, detailed objective of the work. Confusingly, this main sentence is referred to as the “topic sentence,” even though it actually communicates the main idea, not just the topic.
Each paragraph within a work will have a main idea that relates back to the overall main idea of the entire paper. The overall main idea relates to the topic of the paper. The details throughout the written work that aren’t the main idea will support the main idea of each paragraph, and thus the entire work.
To figure out the topic of a work and the main idea of the paragraph you’re reading, ask yourself, “What is this about?” Answer the question both in broad terms and in detailed terms. Pay attention to repetitive words, which will tell you what the paper is focusing on. Understanding the topic and main idea in a written work is a large step toward understanding the purpose of the work. However, uncovering the purpose of a work goes beyond simply breaking down the work’s main points. It also involves our own interpretations that rely on our own knowledge, beliefs, experiences and definitions of certain words.