Developed in the 70’s, computational complexity is a subbranch of the theory of computation. The latter was established by Alan Turing. Computational complexity attempts to discover whether a particular algorithm or computer program is going to be efficient or inefficient. So for example let’s take sat nav. You type in your destination and what happens is a computer inside the Sat Nav – which is reflected in the Turing Machine – does a calculation: it looks at all the potential routes and finds the one that is either the shortest or is going to take the least time.