A capital idea

The Transform component is listed as Transform with an uppercase T. When we refer to it in code, we use a lowercase t. In the Script Reference, it has an uppercase T again. But, if you've already made the mistake of using an uppercase T in your code, Unity threw you an error in the console window. What gives?

Unity's language is case sensitive, which means that a word with a capital letter is treated as a completely different thing than the same word with a small letter. So, transform and Transform are as different from each other as the words night and day.

Transform is a class. A class is like a blueprint that you use to make other things. You might implement power-ups in your keep-up game. Your capital-P Powerup class describes what a power-up should look like and how it should behave. You might create a new power-up using your Powerup class, and label it powerup with a small p. The capital-P Powerup class contains the instructions for building something, and lowercase-p powerup is the name you gave to the thing you've built with that blueprint.

So, in this case, capital- T Transform is the class, or blueprint, that describes how a transform works. Small-t transform is the name our GameObject gives to its own transform instance, which was built using the Transform blueprint. This upper-case class/lower-case instance is a coding convention, and so is not shouting at the dinner table; let's follow the convention to keep things civil.

Here are a few more examples to help you understand:

We can use these classes to create multiple copies, or instances, of a thing. The Car class could stamp out many things, which we could call car1, car2, and car3. We could also call those things sedan, convertible, and suv. In Unity-land, the developers decided to call the thing that was created with the Transform class transform. It could just as easily have been called pinkElephant, but transform makes more sense.