Disk errors refer to problems that occur on a computer's storage device, such as a hard drive or solid-state drive. These errors can result from physical damage, software issues, or corruption of data. When a disk error occurs, it may prevent the system from accessing files, leading to data loss or system instability. Common signs of disk errors include slow performance, unusual noises from the drive, or error messages when trying to open files. Tools like CHKDSK on Windows or Disk Utility on macOS can help identify and repair some disk errors, but severe issues may require professional data recovery services.