A function representation is like a recipe for a cake. Just like a recipe tells you what ingredients to use and how to mix them together to make a yummy cake, a function representation tells you what inputs to use and how to process them to get a desired output.
For example, let's pretend we have a function representation for making lemonade. The inputs might be lemons, sugar, and water. The function would tell us to squeeze the lemons to get the juice, mix the lemon juice with sugar and water, and then pour it over ice to make a refreshing glass of lemonade.
But instead of making a yummy drink, we might use function representations to solve mathematical problems. For instance, we could use a function representation to calculate how much money we would make from a lemonade stand, based on how many cups of lemonade we sold at a certain price.
So, a function representation is basically a set of instructions that tell us what to do with certain inputs to get a specific output. It's like following a recipe or a set of directions to solve a problem.