/ software engineering blog by Maryna Savchenko

AWS Cloud. Definition and characteristics



The need to accelerate building and deploying software and high cost of local data centers are two main reasons for Cloud popularity.

What is Cloud?

Simplified, Cloud can be defined as data center that is not yours.

The National Institute of Standards and Technology (NIST) provides more descriptive definition:

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

Clouds are divided into three types by location and ownership:

Cloud computing services also have several classifications:


AWS is the most popular public cloud that contains IaaS, PaaS, and SaaS.


According to NIST, five key definitions of the public cloud have transformed into a definitive standard methodology of operating in the public cloud:


Unlimited access to servers and storage and many management services should make it easier to operate in the cloud.

Limitations or “everything fails all the time”

Cloud consumer should fully understand SLA (Service Level Agreement) given by cloud provider. There is no way AWS can provide zero outage. In case of failure credit is promised to be given. To receive credit if you were down, you will have to prove that you were actually down by providing network traces and appropriate documentation proving that issue was caused by AWS cloud.

Another important point is that redundancy must be built into application design. Application should continue to operate even if compute and storage failures occur.


  1. Learning Amazon Web Services (AWS) by Mark Wilkins.
  2. AWS SLA.