A Mini CD is a Compact disc that is of smaller size, usually 8 cm, instead of 12 cm, for regular CDs. These CDs can hold less data, about 210 Megabytes, or 24 minutes of music. There is also a version which can only hold 155 MB of data, or 18 minutes of music. Mini Cds also come in the shape and size of a business card, these can hold between 10 and 100 MB of data.