Light machine gun

A light machine gun, or LMG, is a type of machine gun that is designed to be used by only one soldier. Light machine guns are often used as squad automatic weapons.
About LMGs.
The caliber of cartridge that modern light machine guns fire are usually less than medium machine guns. They are also usually lighter. However, a light machine gun can be noticed by the role it plays in a battle. Some machine guns, such as general-purpose machine guns, can be used as either a light machine gun or a medium machine gun. If it uses a bipod and fires in short bursts, it is a light machine gun. If it is used on a tripod and fires automatically for a long time, it is a medium machine gun.
It is possible to fire a light machine gun from the hip, or on the move. This pins down the enemy. Marching fire relies on this. Otherwise, light machine guns are usually fired while lying down and using a bipod. 
Ammunition.
Many light machine guns (such as the Bren gun or the M1918 Browning Automatic Rifle) got their ammunition from a magazine. Others, such as the MG 34, could get their ammunition from either a belt or a magazine. Modern light machine guns are designed to fire more bullets that have a smaller caliber. Because of this, they are usually belt-fed.
History.
Light machine guns were first brought into service in World War I to make the infantry more powerful. By the end of World War II, one light machine gun was given to a section or squad. 
Examples.
Two examples of light machine guns are: