Difference between h-bridge, dual half bridge and quad half bridge
A half H-bridge can be used to switch on or off current passing a DC motor, but only in one direction.

A full bridge is formed by two half bridges, and can be used to switch on or off of current passing through a motor (Note 1), in either direction.

Some motor drivers eg, L298N, has two full bridges.

Some motor drivers eg L293D, have four half bridges.

Some motor drivers, eg BTS7960, have only one half bridge.



to 4. above assumes a DC motor, which usually have only one coil. which can be driven by one full bridge.


Stepping motors have two or more coils, and can be driven by two or more half bridges.



References
(1) How to use motor drivers with H-bridge and PWM input, to control direction and speed of DC motors? - EESE, Asked 2020jul16, Viewed 1k times