Hi Andy,
The Easy VPN connection is to allow a VPN tunnel between two network devices (one acting as a server and the other as a client).
The advantage of this is that on the client side there's minimum configuration required (most of the configuration is on the server side).
You can have an Easy VPN for example between two IOS routers (one server, the other client).
So, you have your computer behind the client router.
In Easy VPN, you can chose between NEM mode or client mode.
NEM mode (network extension mode) is basically a site-to-site behavior.
Client mode is like connecting with the Cisco IPsec VPN client (only that you don't use the software because the tunnel is already established).
Let us know if you have any questions.
Federico.