I was asked this question but didn't know what it does. I know chmod and its usages but what does this exactly do ?
Change permissions for file
alpha, allowing write access for all users and execute access for other users in the file's group. That's my interpretation of it anyway, which seems like an odd combination of permissions to set.
http://www.ss64.com/bash/chmod.html - Man pages are our best friends.
In general chmod refers to change mode you can use alpha method to change folder permissions
Alpha method: Using alphabets (w, x, r, u, o, g, a, -, +, =, s, t) to change permissions for a file/folder
u -- User
g -- Group
o – Others
the command allow you to write access for all users and execute access for other users in file's group