Unity's Invisible Units of Measurement

Unity has a largely invisible system of measurement: it's entirely built on a 1 meter scale. This doesn't necessarily mean that an object made elsewhere might be automatically 1m tall, but rather that any primitive 3D object that Unity generates will automatically be 1m x 1m x 1m. Your best bet for this will be a cube, where the dimensions are always consistent and identical.

Here is a walkthrough on what this might look like when you're working in Unity