IPSec VPN is the older type of VPN, and SSL VPN is the newest type of VPN.
Both is protected with a list of protocols (encryption, authentication, hash, etc.) which are available on both VPN types.
IPSec VPN however consists of 2 phases, ie: Phase 1 (UDP/500) and Phase 2 (ESP), while SSL VPN is typically running on HTTPS (TCP/443).
With IPSec VPN, you will have to pre-install the IPSec VPN software, while SSL VPN can either be pre-installed or as it connects, the client can be downloaded and installed remotely.
Hope that helps.
