Can you explain what is meant by horizontal scaling of a system?

Horizontal scaling of a system means increasing its performance and throughput by adding new independent nodes (servers, containers, etc.) that operate in parallel.

Unlike vertical scaling (adding resources to a single server — CPU, RAM), horizontal scaling involves:

• Adding new servers to the cluster
• Distributing the load among these servers (via load balancers)
• Increasing fault tolerance through duplication

Example: instead of one powerful server with 64 GB RAM and 16 cores, you can use 4 servers with 16 GB RAM and 4 cores each, which together handle requests.

This allows flexible scaling of system capacity, easier fault tolerance, and scaling to meet growing loads.