The owner determines the file's user class. Distinct permissions apply to the owner. Files and directories are assigned a group, which define the file's group class. Distinct permissions apply to members of the file's group. The owner may be a member of the file's group. Users who are not the owner, nor a member of the group, comprise a file's others class. Distinct permissions apply to others. The effective permissions are determined based on the first class the user falls within in the order of user, group then others. For example, the user who is the owner of the file will have the permissions given to the user class regardless of the permissions assigned to the group class or others class. Permissions Unix-like systems implement three specific permissions that apply to each class: The read permission grants the ability to read a file. When set for a directory, this permission grants the ability to read the names of files in the directory, but not to find out any further information about them such as contents, file type, size, ownership, permissions. The write permission grants the ability to modify a file. When set for a directory, this permission grants the ability to modify entries in the directory, which includes creating files, deleting files, and renaming files. Note that this requires that execute is also set; without it, the write permission is meaningless for directories. The execute permission grants the ability to execute a file. This permission must be set for executable programs, in order to allow the operating system to run them. When set for a directory, the execute permission is interpreted as the search permission: it grants the ability to access file contents and meta-information if its name is known, but not list files inside the directory, unless read is set also. The effect of setting the permissions on a directory, rather than a file, is "one of the most frequently misunderstood file permission issues". When a permission is not set, the corresponding rights are denied. Unlike ACL-based systems, permissions on Unix-like systems are not inherited. Files created within a directory do not necessarily have the same permissions as that directory. Changing permission behavior with setuid, setgid, and sticky bits Unix-like systems typically employ three additional modes. These are actually attributes but are referred to as permissions or modes. These special modes are for a file or directory overall, not