More and more companies, authorities and institutions are outsourcing their data to external companies, relying on cloud computing. As a result, applications and data are no longer on internal networks, but in the cloud, and access to data, services, and infrastructure is remote.
The cloud is fashionable, it is everywhere, but its definition is a bit nebulous for many people. In its simplest version, cloud computing environment is the use of computing or remote storage resources, via the Internet, the cloud being a metaphor for the network of networks. This definition being broad, the cloud covers a lot of very disparate applications.

In the cloud

Until recently, we used to access our data and programs on the hard disk of our computer, or, in the case of the company, often on a server located on the local network. Today, access to your data and programs can be done via the Internet. The immediate benefit is that you are no longer dependent on a computer or your office presence; your data is accessible from anywhere, anytime, with a wide variety of devices.

Foundations of cloud computing

The term cloud computing first appeared in the United States at the beginning of 2007 when the first edition of Cloud Expo in New York was launched. Several terms currently designate this new concept in French: "cloud computing", "cloud computing", "cloud computing" or "cloud computing". The reference to clouds (cloud in English) comes from the fact that the Internet is often represented in the form of clouds in the diagrams that illustrate the interconnection of networks, in particular to symbolize virtual omnipresence. For the sake of pragmatism and terminological coherence, only the term "dematerialized computing" is used in this article.

Cloud computing comes in three flavors:

1. IaaS (infrastructure as a service), infrastructure service
This is the low-level version of the cloud computing environment service. This is essentially the rental of virtual machines on which the client can install the operating system and software that suit him.
2. Platform as a Service (PaaS) Platform Service
This release adds the provision of a preconfigured software environment to the infrastructure. For example, in the case of a virtual server, the provider provides, installs, and maintains the operating system.

The risks of cloud computing

Relocation of data is always risky. In this respect, cloud computing poses among other things the problems listed below.
• Loss of control over the data
• Lack of separation and isolation of data
• Non-compliance with legal provisions
• Access of foreign authorities to the data
• Captivity
• Data loss
• System and network failures and unavailability of resources and services
• Misuse of data
The cloud model allows to revive the thin client specific to old client-server architectures. The Chrome book is an example of a thin client where most data and applications are in the cloud. The computer is reduced to the role of displaying interfaces. The advantage is to be able to provide low-cost workstations, which is significant in both the education world and the company. Cloud computing environment is essentially the use of computing or storage resources over remote servers over the Internet, resurrecting the client-server architecture. Which is a concept finally very simple.