Difference between * and none in ACL ServiceNow

1. None–> None is Row level ACL is when we use like table_name.none. Where none says that it is not targeting specific to any field.
2. * –> Table.*  is a field level ACL which gives Access to all field on that table

Example:

Operation to Perform: Read Permission

First ACL created: incident.none (role required snc_read and snc_read_admin)

Second ACL created: incident.* (role required snc_read_admin)

Result: only user with snc_read_admin can have read access incident.* is only providing snc_read_admin role a read access. (This happens because both has snc_read_admin common)

but if:

First ACL created: incident.none (role required snc_read_admin)

Second ACL created: incident.* (role required snc_read)

Result: User with snc_read role only will not view any record because he only have read access at the field level and not on the record/row level.