>>13673427>>13673430Even if you don't understand the math, a surface integral, in concept, isn't too hard to understand. Take the surface of any random figure like a sphere. Look at only the outside surface and break it up into very little "parallelogram" sections like a grid on a globe. Each section of the circles surface is associated with a vector that points directly outward and perpendicular to the section of the surface it's "attached" to. This normal vector is scaled by the area of the section its coming out of. To find Flux, you take the amount of field (in this case magnetic field) passing through the specified surface boundary, and only consider the component of the field vector that's parallel with the normal vector (or in other words the part of the magnetic field that's perpendicular with the unit of area its going through), and you add this up for every point on the surface the field crosses
