If we only have sugar and water, we can make wet sugar, sweet water, syrup, sherbet, or caramel.

A man, a woman, and a teenager could be a family, coworkers, a boss and subordinates, camp counselors and a child. Two electrical elements could be parallel or serial connected. If one of them is broken, then a resulting circuit will or will not work depending on the type of connection.

Not only a group of elements is important here, but also a method connecting them. What place in the whole system does each element take? What task does it have? What signal does this element have to transfer to the next one? How will the next element use the output of the current one?

Also, the places in a system where you will most frequently find any reasons for problems are connections between elements. In social media connections most often are represented by conversion rates.