What is the difference between a cloud and server?

What is the difference and similarities between cloud computing and client /server architecture of traditional model?

• Answer:

  OK two great questions, let start by defining Cloud Computing If you look at the NIST definition of Cloud Computing (which is as good as any definition) Cloud computing is defined with these essential Characteristics: On-demand self service Broad network access Resource Pooling Rapid Elasticity Measured service Cloud computing are then offered as the following service model, think about these as a X as a service (XaaS) Software as a service (SaaS) - The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through either a thin client interface, such as a web browser Platform as a Service (PaaS) - The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages, libraries, services, and tools supported by the provider Infrastructure as a Service (IaaS). The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software source: http://csrc.nist.gov/publications/nistpubs/800-145/SP800-145.pdf Common for all three models are the user does not have access to the underlying infrastructure. Client Server Model Some examples: Web Server, Email Server and File server. A server shares its resources which can then requested by one or many clients over a network. --- With these two definitions in place lets get back to your question: What's the difference between traditional client-server model and the newly hyped 'cloud' model? You can to some extent say that Client Server is the way an application communicates and functions, and cloud computing are the way this application are delivered to use as a consumer of said service. Example: GMAIL: Client Server Communication, your client uses it's web browser to communicate with GMAIL backend servers which then returns the gmail webpage. This service are delivered then delivered to you as SaaS. This means that you are only interacting with the webpage (service part), not with any of the infrastructure, such as servers, network switches, OS, security, redundancy etc. You are just getting the service. Another way to look at a service is how you consume electricity. You basically turn on the powerswitch and presto electrons begin to flow and lights turn on. You are not worried about how it's produced, or delivered. Do legacy webmail services fall into the cloud services category? For you as a consumer, one could argue it's SaaS. NIST defines that SaaS must be deployed on a back-end cloud service, well heck what does that mean then? Is that just deployed on IaaS? Lets explore how a cloud service might looks like from inside. Two things really make a cloud service: Scale Out + DevOps. Scale out  Why purchase 6 latest generation servers, when I can buy 10 last year generation for half the price and get double the performance? Scaling out compared to scaling up rules. This concept allows cloud providers predictable cost models, utilization and upgrade paths. DevOps Why mention DevOps? You can think of DevOps as tasked to DEVelop a service and Operating this service. Why is this interesting? because developers under this model will not physically go down and rack a new server if more resources are needed, nor have I seen any developers patch network cables in our Data Centres. They rely on characteristics from the cloud services such as: Integration, Automation and API's. This allows to turn the HW into a software defined Data Centre (another great industry buzz word...maybe buzzword of 2015?) The DevOps will basically treat the HW as SW using API's. So instead of racking that server, no problem, just write a command an another server will appear on the network, need more storage, no worries let's run another API and storage shall be available. Both properties on IaaS. To answer your question, Cloud is rightful a great buzzword taken over by marketing. Will we still be be talking about cloud in a few years time? probably not. It will all be about the services we can consume and properties of said services. Cloud will just be a deployment and costing model. Not to say that there hasn't been a paradigm shift, both from consumer perspective with Internet of Things and mobile devices. To service creators which has access to such tools as Big Data and Cloud Computing.