File Permission on Linux

a) Number for permission

4 Read
2 Write
1 Execute
 
1 Owner User
2 Group
3 Other
 
Example 600, 777

b) File permission explanation

drwxrwxrwx 
d=directory
r=read
w=write
x=execute
 
Example 0777

c) Change permission

chmod 777 yourfile

d) Change ownership of a file

chown root,root yourfile