A great article on explaining what OTV is and how it compares to VXLAN
As you get more and more into Cisco Data Center terminology you come across the term DCI. DCI is a Data Center Interconnect. DCI’s typically come in 3 categories.
Dark Fiber (CWDM/DWDM)
MPLS Layer 2 VPN (VPWS/VPLS)
MPLS Layer 3 VPN
A DCI is basically a LAN extension over one of the above methods.