In this chapter, we will learn the basics of the cloud and cloud security.
To understand cloud security, we first need to understand the types of clouds and their architecture. There are many global standard organizations such as NIST and CSA who are defining the different aspects of clouds.
As per the NIST definition of cloud computing (https://www.nist.gov/programs-projects/nist-cloud-computing-program-nccp), in simple terms we can say that the cloud offers on-demand accessibility of computing, networking, storage, databases, and applications. Here you do not have to worry about the purchase of physical boxes (CapEx) to run your application. You pay the cost of the resource based on the usage (OpEx).
CapEx stands for capital expenditures and denotes one-time cost investment to purchase any resource, for example, the purchase of a physical server.
OpEx stands for operating expenditures and denotes expenses to make the resource operational, for example, the purchase of manpower, power, OS, and so on to make the server operational.
We can say that the cloud provides abstraction of the underlying infrastructure using hypervisors and orchestrates to allocate resources to multiple tenants from the aggregated resource pool on demand.
The cloud offers multitenancy, agility, scalability, availability, and security. Let's understand what all these terms mean.
We will cover the following topics in this chapter:
- Types of cloud
- Cloud security
- Shared responsibility model
- Key concern areas of cloud security