The torus is a hollow-shaped electronic device of revolution. For us to understand the torus has the same shape as a donut or ring. The coil is wound through the hole in the torus and around the outside. An ideal coil is evenly distributed around the circumference of the torus. The symmetry of this geometry creates a circular loop magnetic field within the core, and the lack of sharp bends will limit virtually the entire field to the core material. This not only makes it a highly efficient transformer, but also reduces the electromagnetic interference radiated by the coil.
The core is a magnetized element that makes the electric current go through a conductive wire, which is the coil, transforming into a magnet.
Ferrites are ferromagnetic devices with a high storage capacity for magnetic fields.
A spool is a device on which other material is wound to be stored.