Search, planning and optimisation
These classic AI sub-fields answer the question: which option should we choose, and in what order?
What is it?
Search, planning and optimisation are classic areas of AI. Search explores possible routes to a goal, planning sets the order of steps, and optimisation picks the best option according to a chosen measure.
An everyday example
A delivery system plans a route but has to balance traffic, costs and delivery deadlines at the same time.
Why does it matter?
These methods quietly power navigation, timetables, logistics and games. They are often more reliable and cheaper than large models.
A common misconception
That there is one single best solution. “Optimal” always means optimal by a measure someone chose, such as fastest or cheapest.
In more detail
What is search?
Exploring possible states or routes to a goal, for example the shortest route between places.
What is planning?
Putting together a sequence of actions while taking goals and constraints into account.
What is optimisation?
Finding the best, or a good-enough, solution according to a measure such as time, cost or error.
Why is there not always one best solution?
Because goals can conflict: the fastest, the cheapest and the safest are not necessarily the same choice.
Remember: “Optimal” always means optimal according to the chosen measure.
Reliable sources
Last reviewed 1 November 2026. An explainer, not professional, legal or medical advice. For rules and figures that change, check the official version.