The difference between the two figures is very simple. Theft consists of the stealing of someone else's property without using violence, force or intimidation while robbery consists of appropriating the property of others using force (forcing or breaking doors, windows or any other means of access), violence (physical) or intimidation (verbal or gestural).
Centralisation refers to a system of government or administration in which major decision making is centralized at the centre in the hands of central government officials or administrators. Major decisions are taken at the headquarters and sent down to the regional or branch offices for implementation.