File access describes the way files are organized on storage media and the way an operating system makes files available. File access depends on the type of storage medium.
While file access was sequential in the years when magnetic tapes were used, it is now index-oriented. However, there are still files that are processed sequentially. These include text files. In these files, data is appended to the end of the text file or written on top of the file contents. Reading is done sequentially in the same way as writing.
In addition to sequential file access, there is also random, quasi-random, direct, and implicit. Index-based files can be accessed by an index based on their position on the storage medium. Virtual Storage Access Method (VSAM) is one of the index-based methods.