Horizontal vs VerticalHorizontal refers to physical space from left to right, or space that is parallel to the horizon. Vertical refers to space from up to down that is perpendicular to the horizon. For example, a person laying on their back on the beach is in a horizontal position and a person standing on a beach is in a vertical position.
Left to Right
Up to Down
Parallel to horizon
Perpendicular to horizon.
Laying on beach
Standing on beach
Horizontal Scale vs Vertical ScaleHorizontal and vertical are used as analogies for scaling resources such as computing power. Horizontal scale is achieved by adding more of a resource such as more computers. Vertical scale is achieved by upgrading what you already have such as adding more memory to a computer or replacing a computer with a faster model. Traditionally, scale was achieved with vertical sale by buying a powerful computer such as a mainframe. It is now far more common for computing to be scaled horizontally using a technique known as cloud computing whereby many computers work on the same problem or service. This analogy can be applied to other resources. For example, you could transport 30 people by buying a bus — vertical scale. Alternatively, you could transport the same number of people with 5 cars or 30 bicycles — horizontal scale.
Add more of a resource.
Add a larger or more powerful resource.
Cloud computing — many inexpensive computers
Mainframes — one powerful computer
Transport with a small vehicle such as a car or bicycle.
Transport with a large vehicle such as a bus or train.
Business expansion at the same level of the value chain.
Business expansion into new levels of the value chain.
A pen manufacturer that begins to manufacture pencils.
A pen manufacturer that opens its own stationery shops.