A satchel charge is a type of explosive device that looks like a little bag or pouch. You can think of it like a big firecracker that you can carry around with you. The satchel charge has explosives inside that can be detonated to cause a big explosion.
Satchel charges were used a lot during wars to blow up things like walls or buildings. Soldiers would bring the satchel charge with them and then place it on the target they wanted to blow up. They would then set the detonator to make the explosion happen.
Satchel charges are also used by some people like construction workers and miners to help them break apart rocks or other hard things.
Overall, a satchel charge is a little bag filled with explosives that can be used to cause a big explosion to blow up things like buildings or rocks.