PUBLIC CLOUD A public cloud is a type of cloud computing in which a third party service provider makes computing resources—which can include anything from ready to use software applications, to individual virtual machines (VMs), to complete enterprise grade infrastructures and development platforms—available to users over the public Internet. These resources might be accessible for free, or access might be sold according to subscription based or pay per usage pricing models. How PUBLIC CLOUD works? A public cloud relies on a virtualized environment to provide an extension of a company’s IT infrastructure, allowing that company to host certain aspects of its infrastructure and services on virtual servers that are offsite and owned by a third party. Public cloud service providers have different strengths, and they offer a wide variety of services and pricing models. Companies that are considering a migration to public cloud need to carefully consider their options when it comes to choosing a provider, especially if they will be locked into a long term contract. Careful planning can help to keep costs down on monthly cloud services bills, but organizations with unpredictable public cloud usage may find it hard to avoid spending a lot of money on public cloud services when usage suddenly surges. Because servers in the public cloud share data from multiple companies, security in public cloud is another issue that IT managers will want to weigh. Encrypting data is a good way to ensure stronger security, but if you are using a combination of public and private cloud (also known as a hybrid cloud), not all encryption platforms work across both public and private clouds. There is also an inherent security risk whenever data is moved between a private data center or private cloud and a public cloud. One last consideration is the location of your public cloud service provider. Data privacy laws in many countries require certain types of data to be stored in country. These laws change frequently, so it’s a good idea to choose a cloud service provider that is located in your country and can confirm that the servers where your data will be stored are local and in compliance with regional laws. There is also the issue of latency—if your data is being hosted on a different continent, it may take longer than if it were stored close by. What makes PUBLIC CLOUD? 1. Resource allocation: Tenants outside the provider’s firewall share cloud services and virtual resources that come from the provider’s set of infrastructure, platforms, and software. 2. Use agreements: Resources are distributed on an as needed basis, but pay as you go models aren’t necessary components. Some customers—like the handful of research institutions using the Massachusetts Open Cloud—use public clouds at no cost. 3. Management: At a minimum, the provider maintains the hardware underneath the cloud, supports the network, and manages the virtualization software.