The RB433GL has three miniPCI slots, three Gigabit Ethernet ports and one USB port for storage or a 3G modem.
Three Gigabit Ethernet ports and three miniPCI slots gives you plenty of options- it can be high speed Gigabit Router, sector AP, wireless backhaul, firewall etc. Powerful Atheros 680MHz CPU, 128MB of RAM and Level5 RouterOS license provides required horsepower.
Differences between RB433GL and RB433AH can be seen in the file (RB411L differences) in the left hand menu.