AccountDescription
Local System AccountAlso known as the NT AUTHORITY\SYSTEM account, this is the most powerful account in Windows systems. It is used for a variety of OS-related tasks, such as starting Windows services. This account is more powerful than accounts in the local administrators group.
Local Service AccountKnown as the NT AUTHORITY\LocalService account, this is a less privileged version of the SYSTEM account and has similar privileges to a local user account. It is granted limited functionality and can start some services.
Network Service AccountThis is known as the NT AUTHORITY\NetworkService account and is similar to a standard domain user account. It has similar privileges to the Local Service Account on the local machine. It can establish authenticated sessions for certain network services.