Conventional warfare is like a big playground fight, but with lots of people and weapons!
Imagine that you and your friends decide to have a big game of tag, but instead of just running around and tagging each other, you have to use things like water balloons and nerf guns to get people out.
Now imagine that instead of just playing with your friends, you have teams of lots of people, and instead of water balloons and nerf guns, they have things like tanks and guns.
That's what conventional warfare is like. Except instead of playing around and having fun, real people get hurt, and sometimes even killed.
The people who fight in conventional wars are called soldiers, and they have to train really hard to be good at what they do. They wear special uniforms, helmets, and sometimes even body armor to protect themselves.
They also have different jobs on the battlefield. Some soldiers use guns to shoot at the other team, while others drive tanks or fly planes to drop bombs on the enemy.
Most countries have armies that are trained for conventional warfare, in case they ever have to go to war against another country. But war is always a last resort, because it can be really expensive and dangerous.
That's why countries try to avoid fighting with each other if they can, and use things like diplomacy and negotiation instead. But when all else fails, soldiers have to be ready to protect their country and fight for what they believe in.