In case of other storage devices , like CD , DVD , magnetic disc we directly access data due to tracks and sectors , we can jump directly , but in case of magnetic tape if we want to access data which is at the middle of the tape have go through all the data before it .
Magnetic tape is working of the sequential access method means if you want to access data stored at the second place than you have to go through the first place data first then only you can access second place data..