Physical verification of the design, involves DRC(Design rule check), LVS(Layout versus schematic) Check, XOR Checks, ERC (Electrical Rule Check).
XOR Check involves comparing two layout databases/GDS by XOR operation of the layout geometries. This check results a database which has all the mismatching geometries in both the layouts. This check is typically run after a metal spin, where in the re-spin database/GDS is compared with the previously taped out database/GDS
ERC (Electrical rule check) involves checking a design for all well and substrate areas for proper contacts and spacings thereby ensuring correct power and ground connections. ERC steps can also involve checks for unconnected inputs or shorted outputs
Thats enough?