ls command provides information about a file.  In Linux everything is represented as a file. A sample output of ls -lh is give below.

Total: show total size of the folder.

File type: First field in the output is file type. If the there is a – it means it is a plain file. If there is d it means it is a directory, c represents a character device , b represents a block device.

Owner: This field provide info about the creator of the file.

Group: This filed provide info about who all can access the file.

File size: This field provide info about the file size. By default the ls -l command give output in bytes.

Other field are self explanatory.

Now permission can be divided into three parts: Owner, Group, Other

r: read permission
w: write permission
x: execute permission

Octal values are used to represent permissions.

4 -> read permission
2 -> write permission
1 -> execute permission

Example: If a file have 764 permission it means owner can do all operation on file, group can do read and write operation on file and other can read only the file