Magnetic hard drives, or HDDs, are storage devices that use magnetic disks to read and write data. They consist of spinning platters coated with a magnetic material, where data is stored in the form of tiny magnetic fields. A read/write head moves over the platters to access or save information, making them suitable for large amounts of data storage. Despite being slower than solid-state drives (SSDs), HDDs are often more affordable and provide higher storage capacities. They are commonly used in personal computers, servers, and external storage solutions, making them a popular choice for users needing extensive data storage at a lower cost.