The system console is a terminal that has special attributes and is used for certain purposes. For example, kernel messages that are meant for an administrator are sent to the console and not other terminals.
A terminal is a means of interacting with Oracle Solaris. Your system's bitmapped graphics display is not the same as an alphanumeric terminal. An alphanumeric terminal connects to a serial port and displays only text. You do not have to perform any special steps to administer the graphics display.
A terminal could also be associated with the physical monitor and keyboard layout of a computer. What sets the graphical terminal apart is that it must be associated with the graphics card and monitor of a computer. So, instead of transmitting characters out of a serial port, the characters are drawn onto the memory of the graphics card that is in the computer.