In this video, you will learn how to determine if a graph represents a function. The teacher explains the importance of correctly plotting the input and output values on a coordinate grid and emphasizes that every input must have exactly one output for it to be a function. The video also discusses the concept of a function being one-to-one, where each input has a unique output. Through clear examples and explanations, you will gain a solid understanding of how to analyze and identify functions using their graphs.