Scalable hosting is essential for business owners, because if your business is likely to grow then your hosting needs to be able to grow with it. Scalability means that when the visitors come flooding in you can easily add extra storage, bandwidth and a small army of CPUs to deal with your enthusiastic new customers. That’s why a lot of businesses rely on cloud hosting because it’s the most scalable solution.
Vertical scaling means adding more power in the form of additional (or more powerful) CPUs and/or extra RAM to your Web server to improve its performance.
In contrast to vertical scaling, horizontal scaling means adding additional machines to meet higher demand, so any extra traffic will be shared out amongst them and their extra horsepower.