This guide explains Linux file permissions in a beginner-friendly way with examples.
Why file permissions matter on a VPS
Every file and folder on a Linux server has rules attached to it.
These rules decide:
Who can view files
Who can edit files
Who can run programs
Who can access directories
Without permissions, any user or process could modify system files, steal sensitive data, or break applications. Permissions are one of Linux's biggest security features.
On a VPS, they protect things like:
Website files
SSH keys
Databases
application configs
Backup scripts
System services
A single bad permission setting can expose your entire server.
Understanding the three permission types
Linux permissions are built around three actions:
Read (r) - view a file or list a directory
Write (w) - modify a file or directory
Execute (x) - run a file or access a directory
These permissions work differently depending on whether you’re dealing with files or folders.
For files:
r - lets you read the file
w - lets you edit the file
x - lets you run it as a program or script
For directories:
r - lets you list files inside
w - lets you create or delete files
x - lets you enter the directory
Without execute permission on a directory, you cannot access it — even if you can read it.
The Three Permission Groups
Linux applies permissions to three categories of users:
User (u) - the owner of the file
Group (g) - users assigned to the same group
Others (o) - everyone else
This creates a flexible permission system in which different users can have varying levels of access.
How to View Permissions
The most common command is:
ls -l
Imagine we receive a result as follows:
rwxr-xr--
This string is actually an expression of three different sets of permissions:
rwx is for Owner permissions
r-x is for Group permissions
r-- is for Others permissions
Let’s add them together to get a permission set based on the following rules:
r (read): 4
w (write): 2
x (execute): 1
If we take our example, we will get the following permissions:
Owner: rwx = 4+2+1 = 7
Group: r-1 = 4+0+1 = 5
Others: r-- = 4+0+0 = 4
Together, we are getting a permission set - 754.