Vertical Integration Definition

I lately tried to define vertical markets. I came across vertical integration, which is also worth giving a definition to.

 Vertical integration refers to the process of acquiring or establishing business operations within the same production vertical. 

Below is an example of vertical integration:
Where an element of the chain (usually manufacturer) tries to control the entire chain till being able to provide to the consumer.

example : Apple, taking over the distribution and retail through the Apple stores.