Answer:
The meaning of the alliance system is when countries work together to achieve a common goal. this means that when a country is in need, the other countries help them out. this is why the Austria- hungary and Serbia war resulted into a general war involving many country.
Step-by-step explanation:
The Hungarian empire declared war on the slavic country of Serbia following the assassination of a crown prince of the Austrian Hungarian empire by a serbian nationalist. This made the Slavic Russians that had an alliance with serbia to declare a war on the Austrian Hungarian Empire and mobilised their troops to defend serbia their ally.
Futhermore, Germans had alliance with Austria Hungarian Empire also declared a war on Russia. This made France and England to declare war on Germany because they had alliance with Russian. All these led to the general war that involved many countries.