The permissions option allows you to set access rights to specific users and groups of users. The default/recommended permissions for directories is 755 and for files 644 or 755.
Here is a list of some common settings, numerical values and their meanings:
-r–r–r– (444) Everyone can read only.
-rw——- (600) Only the owner has read and write permissions.
-rw-r–r– (644) Only the owner has read and write permissions; the group and others can read only.
-rwx—— (700) Only the owner has read, write and execute permissions.
-rwxr-xr-x (755) The owner has read, write and execute permissions; the group and others can only read and execute.
-rwx–x–x (711) The owner has read, write and execute permissions; the group and others can only execute.
-rw-rw-rw- (666) Everyone can read and write to the file. (Be careful with these permissions.)
-rwxrwxrwx (777) Everyone can read, write and execute. (Again, this permissions setting can be hazardous.)
Here are some common settings for directories:
drwx—— (700) Only the user can read, write in this directory.
drwxr-xr-x (755) Everyone can read the directory, but its contents can only be changed by the user.