There are 3 different types of drives, Hard disk, USB and Flash. They can all be different sizes, types and can be used in different ways.
Flash drives are small, portable hard drives that can be inserted into a USB port for storage and retrieval of data. They will provide you with storage space for your data. You can also transfer information from one place to another.
USB drives are removable drives that are used to store important information from the computer. This information can include Power points, Word documents, Music, Pictures and any other documents on your computer. The sizes of USB drives usually range from 8GB to 32GB.