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- Cloud computing is a term used to describe the provision of services for data storage, applications and collaboration through an online system, accessed over a network.
- Cloud services will not work unless network access is available, but as network access has become more common and more reliable, cloud computing has become more popular.
- Cloud computing services are available from any location that is on the network. This makes access to cloud services very flexible. It also means that local storage does not have to be used to store data, as it can be stored "in the cloud" (i.e. on the servers of the company providing the cloud service).
- There are different configurations of cloud services, including public cloud, private cloud and hybrid cloud.
- There are different types of cloud based services, including applications, storage, infrastructure and platforms.
Cloud computing is a term used to describe the provision of services for data storage, applications and collaboration through an online system, accessed over a network. Cloud services will not work unless network access is available, but as network access has become more common and more reliable, cloud computing has become more popular.
Cloud computing services are available from any location that is on the network. This makes access to cloud services very flexible. It also means that local storage does not have to be used to store data, as it can be stored "in the cloud" (i.e. on the servers of the company providing the cloud service).
Behind the cloud services, companies maintain servers that are set up to provide services to each user. This setup can be highly complex, as servers are spread around the world and requests are balanced out between servers to handle high volumes of traffic. Cloud servers hold large volumes of data and must also make sure this data is up to date at all locations. Cloud computing architecture allows companies to design a system that can scale from handling hundreds of users to millions, without redesigning their applications.
Public cloud services are "internet-facing" and available for any user to log in and use. Access to data in the cloud is still controlled (users cannot see each other's files, for example) but access from the Internet makes this a more open approach than a private network. Whilst security issues caused by the possibility of uninvited users can be important in a public cloud service, companies that use public cloud services can be reassured that the providers are providing the same level of security to all parts of their service, which may mean an effective level of security for each organisation using the services. For this reason, public cloud providers like Amazon and Google, who provide cloud services through their own servers, are popular with businesses.
Private cloud services are privately accessible, self-hosted servers which can be accessed from anywhere within an organisation. This allows widespread sharing of documents and communication without user accounts being accessible from a public cloud provider. A private cloud will be expensive to set up, as a company must set up its own data centre operations to maintain servers for the cloud services to run on.
Hybrid cloud services combine publicly accessible services provided by external companies with privately hosted services. An example of a hybrid cloud would be a company that provides web-based email using a major external provider such as Microsoft or Google, but has access to an internal, private file server that is hosted securely onsite in an office, rather than on the servers of an external provider. This means that the company has minimal hardware and maintenance costs but can have most of the benefits of cloud-based services available to users.
Cloud-based services come in many forms, just as applications for computers do.
- Storage services such as Google Drive, OneDrive, Dropbox or iCloud can be used to store media files and documents, accessible from any computer.
- Application services such as Office365 and Google documents allow users to create and edit documents through a web browser, storing or downloading the final version.
- Infrastructure - providing scalable computing power in the form of "virtual machine" servers. The RAM, CPU and backing storage of the servers can be changed and servers can be copied easily. The user can run any services or software on on the machines.
- Platform - a pre-set application for building a website or online program that can be customised and set up to produce a software solution. Instead of an application like a word processor, a platform would be an installation of Drupal, a content management system, or a program running on Google's App Engine, a platform for running code on Google's servers.
Advantages of cloud-based services
- Cloud-based services are accessible from anywhere.
- Cloud-based services can expand storage and processing resources automatically (the provider will always have extra capacity!)
- Security across the service will be strong, as the company providing the service specialises in making it secure.
- Less hardware and management of hardware takes place in each company that uses cloud-based computing
Disadvantages of cloud-based services
- Network must be available for cloud services to operate
- Network bandwidth must be sufficient for data transfer between the client computer and the cloud service
- Security is taken out of the hands of the company and placed in the hands of the provider
- The legality of storing personal data in different areas of the world (or not knowing its exact location) can be problematic.