Magnetic field lines Definition and 52 Threads

I always thougth the "dotted lines" illustrating the direction of a magnetic field were only a tool for vizualizing this direction... Now I read that the definition of a weber equals 10^{8} field lines. So does this mean that the field lines really exist as discrete lines along the direction...

Magnetic field lines? So I'v been taught throughout high school and now in college that a magnetic field has "lines of force". Also that they aren't just lines, but more like big shells around the magnet. But not one of my professors or teachers could give me a reasonable answer as to why...