Magnetic lines of force of a bar magnet shown by iron(Fe) filings on paper

A magnetized needle is floating in the air next to a metal ball

Electromagnetism
Electricity · Magnetism · Magnetic permeability
Electrostatics Electric charge • Coulomb's law • Electric field • Electric flux • Gauss's law • Electric potential energy • Electric potential • Electrostatic induction • Electric dipole moment • Polarization density
Magnetostatics Ampère's law • Electric current • Magnetic field • Magnetization • Magnetic flux • Biot–Savart law • Magnetic dipole moment • Gauss's law for magnetism
Electrodynamics Lorentz force law • emf • Electromagnetic induction • Faraday’s law • Lenz's law • Displacement current • Maxwell's equations • EM field • Electromagnetic radiation • Liénard–Wiechert potential • Maxwell tensor • Eddy current
Electrical Network Electrical conduction • Electrical resistance • Capacitance • Inductance • Impedance • Resonant cavities • Waveguides
Covariant formulation Electromagnetic tensor • EM Stress-energy tensor • Four-current • Electromagnetic four-potential

Magnetism is a force that attracts (pulls closer) or repels (pushes away) objects that have a magnetic material like iron inside them (magnetic objects). In simpler words, it is a property of substances which pull closer or repel other objects. It is a subject in physics.