The main difference between the public cloud and private cloud is where it is hosted and who is responsible for managing it. Public cloud uses shared infrastructure, while private clouds use your organisation’s own dedicated infrastructure.

Public cloud platforms, such as Google Cloud, pool resources in distributed data centres around the world that multiple companies and users can access from the internet. Rather than an in-house team, the public cloud providers are responsible for managing and maintaining the underlying infrastructure. As a result, leveraging public cloud services reduces IT operational costs and frees up time for teams to focus on valuable work that directly benefits the business.

A common public cloud example is to think of it as similar to renting an apartment: 

• You pay rent for a single unit
• The building manager handles the maintenance
• You share the overall space with other tenants, with security around your own belongings

Private cloud is similar to a Public cloud. Private cloud is where you are responsible for the upkeep and management of your infrastructure. You could say it’s similar to owning an apartment block, you are able to rent out a room to a tenant, you manage the maintenance and they have to pay for the single unit.

One key warning to this analogy is that property can’t elastically scale whereas cloud resources can, for example, you can’t resize an apartment to a mansion but you can resize the size of the cloud to whatever you want!

Private cloud requires purchasing hardware to meet demand, as well as any licensing costs needed for software applications. Similarly, an on-site IT stack can’t easily accommodate surges in traffic without staff having to purchase and install new resources (which might go unused until the next surge or decay into technical debt). 

Public cloud lets you automatically scale up your compute and storage resources along with the increased security and services you need.