Explain Different Types Of Files Access?

The mechanisms of protection provide a controlled access by limiting the types of file access that can be made. Access can either be permitted or denied; this access or denial depends on several different factors. One of these factors is the type of access requested. Several different types of operations like read (to read from the file), write (to write or rewrite the file), execute (to load the files into memory and execute it), append (to write new information at the end of the file), delete (to delete the files and free its space for possible reuse) or list (to list the name and attributes of the file) may be controlled.

Some other operations such as copying or editing the file may also be controlled. For many systems, these higher level functions like copying and editing may be implemented by a system program that makes lower level system calls. Protection can only be provided at lower level. There are so many other protection mechanisms that have been proposed till now. Each scheme has its own advantages and disadvantages and they must be selected as appropriate for its intended and proposed applications. A small computer system that is used by only a few members of a certain group may not require the same types of protection as will a large corporate computer that might be is using for research or finance etc.