Protection

A UNIX system permissions consists of owner, users, and groups as their primary identification of "permission groups". From there you can go deeper into to the types of permissions. Each file or directory within a group consist of the basic three types, read, write and execute. Owners are exactly what they sound like. Owners are identified and responsible as the one for creating the file, directory or document. Every file and directory has an owner , and that owner has a group owner. Users are an generalization that signifies a practical individual for assignment of privileges and rights in the system. In UNIX a user perhaps can be just that a USER, or possible a type of system operation. Users in UNIX or the lower level of identifying the path to controlling permissions and access to specific sets of files and folders. The permissions at the user level or Read, Write , and Execute. Read is very simple, access to any file is given to read it. You cannot make changes, or edit it anyway. Read is the simplest form of privileges. To edit or modify the data , you need write permissions. This allows the user to open a folder, file or document and not only read it but make changes to it and save it. The execute permissions grants the ability to execute a file and run it as a program.

Groups play a crucial role in UNIX for many reason, most notably the main protection associated with protection of folders and files, privileges. The basic idea of having groups is the main principle of assigning privileges, or rules , for a given file or folder. This can lead to multiple groups with specific permissions that perhaps could have one or two users in different groups, thus limiting their permissions to folders. Directories are not used correspondingly as standard files, the permissions are special. To list files in a directory you need at least read permissions. Any file you wish to add to the directory or remove as well as edit will require the write permission...