difference between chmod 777 and chmod 007
It may suggest that, but it isn't the case.
The first digit is "owner" permissions, the second is "group" permissions - and the owner and group are viewable with ls -l, and the third is "others", which literally means those that aren't either the owner or in the group.
So 007 means that neither the owner or group members can read, write, or execute the file, while everyone else can do all three.
No. 0007 explicitly denies access by the owner and group, regardless of the other permissions.