How to use Parent/Child

Ive used what is called the Master/Slave tool before, but I've never heard of Parent/Child before. Is it the exact same thing? If not how is it different?

The only time I've ever heard the terms master/slave used in computer technology is for IDE hard drives. All 3D apps I've ever used have the parent/child terminology, and some time googling doesn't come up with any results for master/slave in this context.

A parent object causes all children objects to move and rotate the same way the parent object does, although moving children objects does not have any effect on the parent. Children themselves can be parents; e.g., your hand is the child of your arm, and fingers are children of your hand. If that's what master/slave means to you, then yes, it's the same thing as parent/child.