What is the difference between centralisation and decentralisation?

Ans : They both have different meanings and can be put into use according to the circumstances. Centralisation refers to the higher management or central government taking all the decisions. The junior or lower-level individuals have to abide by the decisions taken by the superiors. 

Likewise, in decentralisation, the higher management or central government gives the decisions making powers to the lower-ranked management. This enables them to make decisions based on the current situation on ground realities.