Google Compute Engine is the IaaS component of the GCP that lets you create and run VM on Google infrastructure. Each VM is called a Compute Engine instance. A Compute Engine instance can run Linux and Windows server images provided by Google or any customized versions of these images. You can also build and run images of other operating systems.
You can choose the machine properties of your instances, such as the number of virtual CPUs and the amount of memory, by using a set of predefined machine types or by creating your own custom machine types.