with access to application software. You don't have to worry about the installation, setup and running of the application. Service provider will do that for you. You just have to pay and use it through some client. IaaS (Infrastructure as a service) Provides you the computing infrastructure, physical or virtual machines and other resources like virtual-machine disk image library, block and file-based storage, firewalls, load balancers, IP addresses, virtual local area networks etc. PaaS (Platform as a service) Provides you computing platforms which typically includes operating system, programming language execution environment, database, web server etc.
resources to provide economies of scale Cloud does not require the purchase and maintenance of physical hardware Cloud can provide elasticity to peak load capacity to accommodate spikes in traffic (first day of classes) Cloud can provide failover through the use of availability zones Cloud can provide the ability to easily spin up environments for testing, training, or temporary needs
hardware, storage and network are dedicated to a single client or company. Public cloud: A multi-tenant environment, where you buy a “server slice” in a cloud computing environment that is shared with a number of other clients or tenants.