Given news wrote:

https://technet.microsoft.com/en-us/itpro/powershell/windows/nettcpip/set-netipinterface#example-2-modify-the-interface-metrics

You could change it with a PowerShell, create two scripts, one to prefer
wired, one to prefer wireless.

The PowerShell command to set the metric is:

Set-NetIPInterface -InterfaceIndex INDEX -InterfaceMetric VALUE

To get the INDEX for the adapter, run 'Get-NetAdapter' and look at the
ifIndex column.

I do not understand what a "power shell" is.
I do understand what a "command line" is, so the "netsh" commands working
at a command line make sense to me.

But how do I get to a "power shell command line"?
Googling, I found out I can do this:
Start - Run - powershell
But is that an "admin" power shell?

I really don't understand at all why a second command line even exists.
Can you give me a sentence or two on why I would use powershell over the
command line?