firearms a failure to feed is a jam
that is caused by the ammo not feeding completely into the chamber which leaves the gun in an inoperable condition and out of battery
There are many causes of this ranging from bad magazine feed lips, excessively dirty actions, faulty ammo, use of non standard ammunition or sometimes the use of ammunition type that was not meant for the firearm.
In the event you suffer a failure to feed, keep the gun pointed downrange. If the type of firearm allows you to manipulate the action with the safety on then engage it. If not just try to reciprocate the action to eject the cartridge that did not feed and try to see if the next one in the magazine will feed, if it does then continue your course of fire. If it doesn't, completely unload and inspect your firearm and magazine for damage, also check the condition of your ammo. Nine times out of ten it is faulty ammo that is the culprit if you are using a good firearm in good condition.
Some cheaper makes do have a propensity to jam more than their better engineered or better manufactured contemporaries.