What is the difference between a cloud and server?

Cloud computing: What is the difference between a cloud and a server? Can server be a cloud and vice-versa?

• Answer:

  There's a lot of information on internet to understand what Cloud is but I guess you need something simple and concrete. So here it is. Real life example (explains the major application as well, getting every Compute () need from Cloud is not wise.): You have a varied requirement where you need Servers ranging in both forms numbers and sizes. So you have a requirement of Server ranging from 0.2 CPU, 512MB Memory, 300Gigs DiskSpace (let's classify this as Class 1) to Server with 16CPU, 10G Memory and 10T Disk Space (let's classify this as Class 2). And the amount of Servers you need to get your workload process in a year would be ranging from 2 to 200. So what would you do? Solution A: You buy 200 Servers in one go with mixed proportions of Class 1 and Class 2 servers. Pros: You have all those servers in your lab, they are secured, and you can use them whenver you want. Cons: You are buying hardware which probably you do not need for half of the year, management of hardware in you labs (cooling, maintenance et cetera), After 1 Year what to do with this all hardware?, the hardware you have now is probably outdated. Solution B: (For this you need to read http://en.wikipedia.org/wiki/Virtualization first) So I would buy 500 high end servers (Say X type of hardware which supports virtualization) who can host approx. 25 Class A Virtual machines and 2 Class B Virtual Machines per X type of Servers. Once this is done. I'll give you an interface (Web UI, Rest APIs, Command Line APIs) to create Virtual machines of any of your Class A or B whenever you want and to delete those virtual machines whenever you want. Will provide you network access to the Virtual machines which you would  create and will charge you for the amount of time you have kept a Vitual machine running i.e. From the Instance you created a Virtual machine to the time when you dint need it anymore and deprovision (deleted) it. Now you would ask why would I do this? Because you are not my only customer and I'm letting everyone in the town to provision VMs on my hardware and I'm charging them and reusing my hardware for their VM creation now within the space which was left after you deleted yours. So here 'I' am the Cloud Service Provider, and what I offer is Cloud (it's just a name because it obscures your view of how your vms are created and placed in my hardware and they are all just behind my interface and you can just access them via network, no physical access, which in our terminology we call as is behind the Cloud). So while hoping that this answers your question I would like you to know that this example was just to answer you question. Cloud has a lot, lots and lots of other advantages and how it works. Some pointers for you to look out for to get basic idea of Cloud Computing. Global presence Scalable Highly Manageable On Demand Work Load Migration Infrastructure as a Service (this was me according to above example) Platform as a Service (its you and our major customers) Software as a Service (Customers of Platform as a Service) Virtual Storage, Virtual Network, Images/snapshots