Kernel Vs. User-Space

The Kernel has access to all hardware, the user calls the kernel with specific systemcalls, (e.g., 0 for read and 1 for write) this is usually done with specific subroutines in the C Standard Library (e.g., fopen() eventually executes syscall 0 for read). The User has 0 access to hardware, this improves security and clearly defines what a user can and cannot do. Included in this is automatic logging by the system, this is helpful for tracking privilege escalation and intrusion detection. Diagram of Kernel Vs. User-Space: