You might have also tried to find a comprehensive as well as an easy explanation regarding the same through various websites.
However, the explanations provided over these websites are pretty long and difficult to grasp.
Let’s try to learn through a simple example, what exactly hysteresis in an electronic circuit means.
The behavior of a relay to a continuously applied variable voltage will distinctly explain this. The procedure is as follows:
Take a 12 volt relay, connect a variable power supply to it and gradually increase the voltage from zero to 12.
You will find that the relay activates at about 11 volts. Logically, if now the voltage is reduced below this level, the relay should deactivate.
However, that does not happen. Practically it will be seen that the relay deactivates only after the voltage is reduced well below 9 volts.
This voltage lag between activating and deactivating threshold can be defined as the hysteresis; in this case it is for the relay.
Similarly, all electronic circuit possesses this small disadvantage when it comes to maintaining fixed thresholds levels.
In efficient electronic circuits the level of hysteresis is kept to the minimum. If you have more doubts regarding what is hysteresis, do feel free to respond with your comments.