Ampere's Law:$$\oint \mathbf{B} \cdot d\mathbf{l} = \mu_0 I_{enc}$$, which states that the integrated magnetic field around a closed loop is proportional to the electric current passing through it.
Magnetic Field (B-field): A vector field surrounding magnets and electric currents, where moving charges experience a force. It is measured in teslas (T).
Solenoid:A coil of wire designed to create a uniform magnetic field in its interior when an electric current passes through it. Often used as electromagnets.