Horizontal scalability

Horizontal scalability refers to increasing a system's capacity by adding more machines or servers rather than making a single machine more powerful. For example, if a website becomes slow due to high traffic, adding more servers helps share the load, allowing the site to handle more visitors efficiently. This approach offers flexibility and can be scaled up or down as needed, ensuring better performance and availability. Essentially, it’s about expanding "outward" by increasing the number of resources rather than "upward" by boosting the power of individual components.