When a fence contractor will visit you for your fence installation, he will ask you many questions to understand your fencing needs. One of the common and very important questions would be the purpose of the fence. Fence Master's has a good article - types of chain link fence. If it is for security, then the whole planning ahead will be based on this factor only, and all other factors will be thought of later. Security fences are different, and when you think security, you put aesthetic at last in the priority list, and think of the strongest and most secure options only. Security comes with strength. And hence a fence for security has to be built strong.
Your fence contractor may suggest you materials like aluminum, wrought iron, steel, bamboo, chain link etc. Every style has its own special properties, and contributes to the safety factor in various ways.
This is one of the most preferred types for security fencing. Wrought iron is reasonably priced, and is a very sturdy material. Moreover the iron in it is treated to withstand elements of nature really well, and hence it does not rust or chip off. You will have to paint it when the old paint peels off, and that is all the maintenance it asks for while giving you nice security.