Answer:
Now in simple terms we can have a definition that,"when there are some effects produced inside an market place, which will then contribute to some changes inside the economy of a civilized region are called as the externalities are effects.
Step-by-step explanation:
For example:
Lets, suppose we have cattle in a farm and they will obviously have the feature to produce waste material that will make the soil more fertile. And then we have our crops all grown up healthy and large in number. So, we will get a good market value of that crop been sold. And it was all due to the contribution of cattle's in providing the optimum amount of waste products to add value to the soil fertility.This effect produced by the cattle's waste product is called as the externalities effect.