According to Standards and Technology:

Cloud computing is a model for enabling convenient, on demand network access to a shared pool of configurable computing resources (e.g networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.

After the description of cloud computing, characteristics of cloud computing can be specified.

On demand service: Needs of users can change dynamically. Cloud computing enables these users to consume computing resources such as software and storage when they need and they are only charged by the amount that they used.

Broad access network: Computing resources that users consume reside over the network and these computing resources can be used with different platforms such as laptops, mobile phones, PDAs and personal computers at users‟ site.

Resource pooling: Computing resources are “pooled” at cloud service providers‟ site. It means that cloud computing permits combination of these computing resources such as hardware, software and processing and to supply multiple users in a “multi-tenant model”.

Rapid elasticity and scalability: Computing resources can be immediately supplied. In other words, consumers can increase and decrease the usage of computing resources at anytime they want without contract or “up-front commitment” and this indicates that consumption can immediately increase to meet dynamic requirements of consumers at any time.

Measured service: Computing resources can be used by multiple consumers and meanwhile that each consumer is charged by the amount used, so cloud computing has a dynamic system which measures the usage of computing resources for each consumer and gives response to billing process.

Virtualization: A cloud can include million serves due to large scale feature of a cloud. Users can get service which is defined as virtualization feature of cloud computing anywhere and anytime by using their computers, laptops, notebooks or mobile phones.

Reliable infrastructure: Cloud computing also has a reliable infrastructure meaning serving with minimal downtime and giving rapid response to consumers‟ requirements.

Cost advantage: Consumers have benefit of low cost advantage of cloud computing because buying services over cloud computing is particularly inexpensive.

References:

Chang, E., Dillon, T., & Wu, C. (2010). Cloud Computing: Issues and Challenges. 24th IEEE Conference on Advanced Information Networking and Applications (pp. 27–33). Pert, WA: IEEE.

Mahmood, Z. (2011). Cloud Computing: Characteristics and Deployment Approaches. 11th IEEE International Conference on Computer and Information Technology (pp. 121–126). Pafos: IEEE.

Carroll, M., Van der Merwe, A., & Kotze, P. (2011). Secure Cloud Computing: Benefits, Risks and Controls. Information Security South Africa (pp. 1–9). Johannesburg: IEEE.

Chen, H., Gond, C., Gong, Z., Liu, J., & Zhang, Q. (2010). The Characteristics of Cloud Computing. 39th International Conference on Parallel Processing Workshops (pp. 275–279). San Diego, CA: IEEE.