Access time refers to the time required to retrieve data from where it is stored. It is applied to different forms of memory, including the random access memory RAM as well as the hard disk. Even the CD-ROM has a particular access time, which correspond to the time that the computer takes in order to retrieve data from the CD.
As the time went on, the devices were modernized with newer technology with shorter access times. The fastest access time is the property of semiconductor memories. Magnetic tapes, magnetic disks as well as compact disks are older storage devices, which longer access times.