Because only one bit of all codes change when the code changes and it is unnecessary to match the reading timing in the gray code, it can be read steady compared with other code (the binary code and the BCD code).

The binary code and the BCD code need the one bit strobe signal that takes timing to prevent the reading mistake, therefore a lot of one connecting wires are necessary for resolution.

e.g.

* The Gray code change only 1 bit, the binary code change 5 bit.