# File System Object
Nix uses a simplified model of the file system, which consists of file system objects.
Every file system object is one of the following:
- File
- A possibly empty sequence of bytes for contents
- A single boolean representing the [executable](https://en.m.wikipedia.org/wiki/File-system_permissions#Permissions) permission
- Directory
Mapping of names to child file system objects
- [Symbolic link](https://en.m.wikipedia.org/wiki/Symbolic_link)
An arbitrary string.
Nix does not assign any semantics to symbolic links.
File system objects and their children form a tree.
A bare file or symlink can be a root file system object.
Nix does not encode any other file system notions such as [hard links](https://en.m.wikipedia.org/wiki/Hard_link), [permissions](https://en.m.wikipedia.org/wiki/File-system_permissions), timestamps, or other metadata.
## Examples of file system objects
A plain file:
```
50 B, executable: false
```
An executable file:
```
122 KB, executable: true
```
A symlink:
```
-> /usr/bin/sh
```
A directory with contents:
```
├── bin
│ └── hello: 35 KB, executable: true
└── share
├── info
│ └── hello.info: 36 KB, executable: false
└── man
└── man1
└── hello.1.gz: 790 B, executable: false
```
A directory that contains a symlink and other directories:
```
├── bin -> share/go/bin
├── nix-support/
└── share/
```