Hydronic heating was a wise investment

Have you ever heard of heated floors and/or hydronic heating? I must admit that as a woman who grew up in the deep south, I never really gave heating systems all that much thought. Every person I have ever knew either used a wood stove as an HVAC system or little plug-in space heaters for their winter heating. Soon, though, I will be moving to the northern part of the country. As part of the move, I will be renovating an old farmhouse I inherited. It gets super cold there, so I have to give a lot of thought to the type of heating and cooling system I will choose to install. Right now, there is an ancient oil furnace, which is typical, I suppose. My father-in-law recommends I look into a hydronic heating system. From what I understand, hydronic heating uses water to heat your house. That seems like it might be a wise investment because water is definitely cheaper than oil. But, the water has to be heated by something, and I am wondering if that process is energy efficient or not. Typically, I suppose, the water is heated by a boiler, and then the water is sent through pipes and into the radiators. I do not know how the boiler heats the water. In this method though I have heard that the water is superheated by one of the new fancy tankless water heaters. It all seems really fancy to me and I know little about these yankee winters I will let my husband deal with it