What is horizontal and vertical integration?

Horizontal Integration : When a company decides to expand horizontally i.e within its current line of business then it is called horizontal integration. For eg. pepsi when it got into snacks it can be called a horizontal integration.

Vertical integration: When a firm covers all activity of supply chain then it can be called as vertically integrated. Eg. if a paper manufacturing industry goes into plantation of woods and other activities involved with production raw material (wood) it can be called a vertical integration.