Alternatively referred to as serial access, sequential access is a method of retrieving data from a storage device. With sequential access, the device must move through all information up to the location where it is attempting to read or write. This method is often contrasted with random access, in which the device may move directly to a specified location in memory.
A common example of sequential access is with a tape drive, where the device must move the tape's ribbon forward or backward to reach the desired information. The opposite would be RAM (Random Access Memory) that can go anywhere on the chip to access the information.