Pieces of cucumber and cherry tomatoes are the elements of a system. If we put them in one bowl and add the olive oil, it becomes a salad. If we fry tomatoes and add eggs, then we will get scrambled eggs. If we put them on a toast, it will be avocado toast from the Moroccan French cafe.

Each of these systems has unique properties, for instance, only scrambled eggs are hot. Each of these systems requires unique resources: time, tools, additional ingredients. Each of these systems has a unique way of communicating with the external environment. And if we take a method from one system and put it in the other system, it may destroy the dish.

How can you answer if you need to fry tomatoes if you don't know what you wanna get? It's positive for eggs and negative for a salad. How can you draw a conclusion based on your competitor knowledge if you don't know what you want? Should you make games / polls / giveaways in an account? Should you create multiple stories? Should you try to get the audience to provide comments? There is no correct answer without understanding how exactly each parameter influences your expected result.

Let's shift to the theory part.

A system is a group of interrelated elements that act with a common goal. A system has input (like firewood) and output signals (like light and heat). Therefore, the main task of a system is transforming an input signal to output. Firewood became a warmth. A cucumber became a salad. Time and money became a growth of sales (and more money as a result).