Cloud computing is not one single technology, nor is it one single architecture.

“Cloud computing is essentially the next phase of innovation and adoption of a platform for computing, networking, and storage technologies designed to provide rapid time to market and drastic cost reductions.”

Definition from National Institute of Standards and Technology (NIST)

“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”.

Characteristics of Cloud Computing

    Broad Network Access- Access to resources in the cloud is available over multiple device types. This not only includes the most common devices (laptops, workstations, and so on) but also mobile phones, thin clients, and the like.  

On-demand self-service- In non-cloud or legacy environments, when the end user can self-provision without interacting with the provider, the downstream result is usually extreme inefficiency a1nd waste.

Cloud-based architectures, however, are designed and built with self-provisioning in mind. In cloud computing , the lack of commercial off-the-shelf (COTS) software purpose-built for cloud automation led many companies to build their own frameworks to support these processes. While many companies do still use homegrown portals, adoption of COTS software packages designed to manage and automate enterprise workloads.   

Resource pooling- Resource pooling is a fundamental premise of scalability in the cloud. Without pooled computing, networks, and storage, a service provider must provision across multiple silos (discrete, independent resources with few or no interconnections.)  

Measured service- Measured service implies that usage of these pooled resources is monitored and reported to the consumer, providing visibility into rates of consumption and associated costs. Accurate measurement of resource consumption, for the purposes of chargeback (or merely for cross-departmental reporting and planning), has long been a wish-list item for IT stakeholders. Building and supporting a system capable of such granular reporting, however, has always been a tall order.

Rapid Elasticity- Elastic resources are critical to reducing costs and decreasing time to market (TTM). Indeed, the notion of elastic computing in the IT supply chain is so desirable that Amazon even named its cloud platform Elastic Compute Cloud (EC2).

Other- Agility, High availability and reliability, High Scalability, Multi-Sharing, Device and Location Independence, Low cost & Low Maintenance, Services in pay-per-use mode.

Advantages of Cloud Computing

(1)Lower cost computer software can be use- You can also use lower cost computer you don’t need purchase any heavy software packages because you are not using any software or desktop or laptop you are only using Browser.

(2)Lower IT infrastructure Cost- If you are Using Cloud computing you don’t need to invest in any larger Server.

(3)Lower Maintenance Cost- If you are working In Cloud Computing so you don’t need to maintenance for Hardware & Software cost.

(4)Instant Software Update- Another software-related advantage in cloud computing is that users don't need to face with the choice between obsolete software and high upgrade costs. If the app is web-based, updates happen automatically and are available next time when the user logs in to the cloud.

(5)Computing Power Increase- The execution capacities of cloud servers are very high. It processes the application very fast.

(6)Unlimited Storage Power- Cloud offers you a huge amount of storage capacity like 2000 GB or more than that if required.1

Disadvantages of Cloud Computing

(1)Require Constant Internet Connection- Cloud computing is impossible without Internet connection. To access any applications and documents you need a constant Internet connection.

(2)Require High Speed Internet Connection- Similarly, a low-speed Internet connection makes cloud computing painful at best and often impossible. Web based apps often require a lot of bandwidth to download, as need to download large documents.

(3)Security- With cloud computing, all your data is stored in the cloud. That's all well and good, but how secure in the cloud? Unauthorized users gain access to your confidential data when permission sets are not clears.