Birmingham mumbai

Bit
Meaning
r
The file can be read
w
The file can be written to
x
The file can be executed as a program
•  Directories:
Bit
Meaning
r
The contents of the directory can be viewed
w
Contents of the directory can be altered
x
The user or group can use cd to go inside the directory
As you can see, permissions are read differently depending on their context: 
whether they apply to a file or a directory. In the example of the 
annual_projects
 
directory, 
bob
 has 
rwx
 permissions to the directory. This means that the user 
bob
 can 
do everything (view the contents, add or remove contents, and use 
cd
 to move the 
current directory of his shell into the directory). Regarding a group, members of the 
sales
 group are able to view the contents of this directory and 
cd
 into it. However, 
no one in the 
sales
 group can add or remove items to or from the directory. On 
this object, other has no permissions set at all. This means that no one else can do 
anything at all with this object, not even view its contents.