Span of control is when the head/ boss of a company controls the people directly below him/ her.
Chain of command is when an average worker speaks to someone above them about their problem for example there head of the department.
Delegation is when someone higher up gives out an instruction to someone below them, for example a manager to an average worker.
De-layering is when the head/boss takes out a layer of command because it can make it easier to communicate.
Centralisation is when all decisions of a company stays in one particular place.
Meanwhile, de-centralistaion is the opposite because for a big company like coca cola they will have places all over the globe where decisions will be made.