THE separation of powers is a political doctrine of constitutional law usually defined by the three traditional branches of government (i.e. executive, legislative, and judicial) and is designed to be a system of checks and balances, wherein each branch is given different and differentiated powers. That is the theory.
All democracies, whether mature or not, do recognise such a differentiated and separate concentration of functions of power. Non democracies are silent about these different powers of making laws, executing such laws, and the modus operandi plus interpretation of the same laws.