At present we have already known about VPN (Virtual Private Network) that is the kind of connecting between 2 or more network (WAN to WAN, WAN to LAN, LAN to Lan) to sharing resource from your office. To setup VPN you need hardware like router, gateway for setup VPN, but these hardware are very expensive.
In many time you need to connect your PC or Notebook to your office for using resource and they have many method to connect between your home and office. Exsample method. by using dialup, This way is very easy method to connect your home and office and it very easy to setup too, But this way has very high expense because every time you dial a modem you have lose your money with it.
At present the most of us have connect to internet with broadbrand that has a highspeed more than a dialup and we can use this ability of it to connect your home and office by using VPN software. This way has low cost because you are not paying for a dialup, hardware. The software has very easy to use and config by using software GUI.