Powershell scripts understanding required?

Can someone help me to understand below script notations?

1.) $file = Get-Item -Path $filepath

if($file -ne "")

(What does -ne "" mean in this context. does it mean if file does not exist in the path above?)

2.) cmd /c $command > $null
(What does the > $null mean here. I know that this is a command line execution via powershell but dont know what does > $null mean)