Delete all the contents of a file without deleting the file itself.
Clear-Item is similar to Clear-Content, but works on aliases and variables, instead of files.
Add-Content - Add to the content of the item
Equivalent bash commands: useradd - Create new user accounts
useradd is NOT the equivalent bash command - cannot think what it is but it is not useradd - maybe something like 'cat <NUL >file'.