In this context, a console normally means the device which is used to talk to a computer before its operating system is running. In some cases, a serial terminal, like a VT220 (or some other device which emulates one) is used. In other cases, the computer may have a workstation keyboard and graphic display which (together) can be used as its console.
Long ago, actual terminals (even printing terminals) were common. HP even made some. Now, there are probably more PCs in use running some kind of terminal emulation program than there are actual terminals.
With some operating systems, the console device, whatever it is, may have greater privileges than other terminals, allowing, for example, "root" logins when these are not allowed from other terminals.
A terminal is any character based interface to the system, usually running a login prompt and issuing a command line shell. Generally, _real_ terminals are peripherals to the system. For example, a keyboard and monitor attached to a serial port on a machine on older shared systems.
The console is the main terminal to the system. At boot, that is where the boot messages appear and the first login prompt. When a system is "single user", the console will usually be the only available terminal.
