Okay kiddo, so imagine you have a group of soldiers who are fighting in a war. They have a leader who is in charge of telling them what to do and making sure they stay in line. But what if that leader wasn't doing a good job or was being disloyal to their country?
That's where the commissar order comes in. Back during World War II, the Soviet Union (which is a country in Europe and Asia) had a special group of soldiers called commissars. These were people who weren't exactly soldiers, but they were there to make sure that the soldiers were doing their job and following orders.
So if the leader of a group of soldiers wasn't doing a good job, the commissar could give an order to remove them from their position. They could also give orders to punish soldiers if they did something wrong or if they weren't following orders.
This was important because the Soviet Union was fighting a very important war and they needed everyone to be doing their best. The commissar order was one way to make sure that everyone was working together and doing what they were supposed to.
So in short, the commissar order was a way for a special group of soldiers to make sure that all the other soldiers were doing what they were supposed to during a time of war.