A Ferrite core is a type of magnetic cylindrical core that is made from ferrite, a ferrous material. They are among the most versatile and important pieces of basic electronic equipment and many modern devices would not be able to work without them.
Ferrite cores help to protect against radio frequency interference (RFI) and electromagnetic interference (EMI). As well as these materials having the capability of functioning as the core in a transformer, they also have tremendous capabilities in terms of reducing electrical interference moving to or from devices, and are heavily used in radio equipment.
These cores are designed for noise suppression and are frequently used in antenna and RFID applications. They can also be incorporated into ferrite core chokes, broadband transformers, inductors and other components.
They are usually included as standard on various types of computer cables, though people designing digital data equipment and may end up adding additional ferrite sleeves, beads or other components to cables to reduce interference to a specified level.