What are the risks of logging into a system routing as "root" or some other administrative identity?

"Root" in Linus is the the same as Administrator in Windows.

When you log into a system with identity "root" this means that you have administrative privileges (you are not simple user of the system and application). The risk is that as a "Root" you have the authority to make changes in the system and maybe harm the system if you don't know exactly what you are doing.