Magnetic flux can be defined as:

Magnetic flux is indeed best defined as the total quantity of magnetism, taking into account the strength and extent of a magnetic field. It refers specifically to the lines of magnetic force that are present outside a magnet when considering how magnetic fields interact with their environment. When visualizing magnetic field lines, they emanate from the north pole of a magnet and return to the south pole. This description captures the essence of magnetic flux, as it pertains to the flow of these lines outside the magnet while acknowledging their directional nature.

The concept of magnetic flux is crucial in understanding electromagnetic principles, such as those applied in electrical engineering and physics. It helps to quantify electromagnetic fields and their interactions with various materials and other fields. This definition aligns closely with the broader scientific understanding of magnetism and the fundamental principles that govern it.