What are mortars?
Mortar is a mixture of cement, sand and water. It is used as a binding material in construction industry.
Mortars were a smooth bored of cannon with a high trajectory. They were effective against trenches and fortifications because they dropped down behind walls and barriers. Most of today's modern mortars are actually a type of rocket. Most are smaller sized weapons that can be carried by ground troops to provide some good firepower close by.