Get-Help (help)
You can search by string, help do a string search on the help of the command (if the command have help file)
if we want to restart our computer we going to search command for it
Help *restart* (Help is alias for command Get-Help)
The first one look like what we want
How do we run this command, can you show me? let's tell PowerShell to tell as
help Restart-Computer -Examples