Every file is created with an access mode.
Each access mode grants read, write, or execute permission to users, the user's group, and all other users. The access bits on a newly created file are a result of the reverse of the umask bits ANDed with the file-creation mode bits set by the creating process. For example, if an existing file has the 027 permissions bits set, the user is not allowed any permissions. Write permission is granted to the group. Read, write, and execute access is set for all others.