userspace==unprivileged execution, i.e. cannot directly access i/o ports, devices, etc. Normal applications execute like this. kernelspace==privileged executio

userspace==unprivileged execution, i.e. cannot directly access i/o ports, devices, etc. Normal applications execute like this. kernelspace==privileged execution, i.e. has access to all the resources of the machine, all RAM, all devices, etc. The kernel by definition requires control of the machine because its primary job is to manage resources on behalf of the userspace applications.