External hard drives are portable storage devices that connect to computers via USB or other interfaces. They provide additional space for storing files, backups, and media, making them ideal for users who need extra storage beyond their computer's internal capacity. These devices come in various sizes and capacities, catering to different needs. Using an external hard drive is straightforward; simply plug it into your computer, and it will be recognized as a new drive. They are particularly useful for transferring large files between devices or for creating backups of important data, ensuring that your information is safe and accessible when needed.