tristate implementation

what is a tristate ? what happens if we use a tristate in any circuits??

A device is in tristate mode when its output is disabled or turned off, resulting in very high output impedance. It doesn't source or sink current, and in this way the circuit behaves as if the device isn't even connected. A common implementation is when you have multiple devices connected to a common circuit, or bus, such as a data bus in a digital system. You only want 1 device to be putting its data onto the bus when that device is selected, and no other device is to interfere or corrupt the data you are trying to read from the specific device. This is a common use of tristate for only enabling the output(s) on the device that is selected through some control input(s) on the device, leaving the other, non-selected ones in tristate.