An open-loop system is a type of electronic control where the output of the system isn't monitored and regulated to affect the system's performance. Although simple to operate, the disadvantage is that the user has to monitor the system's output to make corrections to any error in the process.
An example of an open-loop system is a clothes dryer. The user sets the drying time and runs the machine, and the machine runs until the timer is finished, regardless of whether or not the clothes are actually dry. The user has to manually check the clothes throughout the drying process and adjust the time, instead of the dryer using a sensor to determine the clothes' drying level and automatically adjusting itself.