Suspend to RAM means everything you have running will remain in memory, but other devices (like hard disk drive) will shut down. You can continue your work without waiting for the machine to boot again, but keeping the data in memory requires a couple of watts of power, so if there's a power loss, you'll lose it. Suspend to hdd wouldn't do that.

Wake-on-LAN does mean you can boot (or wake up) the machine from network, but you'll need to know the network adapter's MAC address (for example, 12-34-56-78-90-00) and IP address, plus an application that can send the "magic packet" to the card.