Cloud Computing - What is a Computer
Cloud Computing for Beginners and IT Recruiters
What is a Computer?
A Computer is a device which can process a set of instructions given to it, called programs. It is as simple as that. But our goal in this lesson is to understand what makes up a computer? What is inside a computer? A Computer basically contains a System Unit. This unit is connected to a set of Input / Output Devices such as Monitors, Keyboards, Mouse etc.
Computers come in different shapes.For example, a Laptop is a computer. Your Smartphone such as iPhone or Android Phone is a computer. It’s screen acts as both an output and input device. We use the touch screen to input our command to the smartphone. Same applies for your Tablet devices such as Apple iPad or Microsoft Surface.
A System Unit contains many things such as Power Supply, Motherboard, Microprocessor, Random Access Memory, Disk Drives etc. Considering the fact that I first opened a Computer as a Computer Service Engineer in the year 1991, I can talk about these for hours and hours. But that is not the goal of this video series here. We are all about getting to know Cloud Computing.
So let me get to three main components in this. Microprocessor. RAM or Random Access Memory and Disk Drives.
What does a Microprocessor do? It does all the calculations. In other words, it computes. What does it Compute? It computes the set of instructions given to it. In the Cloud Architecture, a processor is referred as a COMPUTE resource. As of now we are way far away from learning Cloud in this video series. So, just remember that a microprocessor is part of the COMPUTE resource in Cloud. If you don’t want to remember it now, no worries. The upcoming videos in this series will make it easy for you to remember. Anyways, though every component in a Computer is very important, we can safely say that every function of a computer depends on the Microprocessor. A microprocessor is also referred as CPU which is an acronym for Central Processing Unit. Now a question. From where do those set of instructions come?
Storage - Hard Disk drive
Mostly they come from Programs stored in the Hard Disk Drives. What is a Hard Disc Drive? It is basically a storage device used to store data. The data can be in a various format. It can be a program file, video file, database etc. These use multiple magnetic coated discs to hold the data. The data is persistent. Meaning that, even if we turn off the computer, the data will still remain in the hard disk. It won’t get deleted or erased. In other words, the hard disks do not need a constant power supply to keep the data in it. I will explain about storage in detail later. But as you can see, this will be part of a Storage resource in Cloud.
RAM - Random Access Memory - Memory
The next important component is Memory. Also known as RAM, which is an acronym for Random Access Memory. Let’s just say if we are given this math problem in a piece of paper and asked to solve it, we would solve it by writing the answer as 8. But what exactly happens while we do solve that. First, as we look at the paper, we transfer these numbers into our memory. Then our brain, having learnt simple multiplication already, does the process of multiplication and derives at the answer 8. Then we write the answer 8 in that paper. In this example, a part of our Brain acts as memory to store these numbers. Then an another part of our brain does the calculation. Point is, the calculation never happens in the paper directly without bringing those numbers into our memory, right?
Like that when we ask a computer to run a program, which is stored in the hard disk, it copies the program into the memory first. The memory here is the RAM. Then the processing is done by the CPU using the copy of the program stored here at the memory. The CPU, aka, Central Processing Unit, aka, Microprocessor is responsible for transferring the program into the memory, keeping track of it and executing it. Once the answer has been arrived, it will be displayed in the monitor in most of the cases, and can be saved in the hard disk as we prefer. In the human analogy, our brain does both the functions of the CPU and Memory. It is responsible for transferring the data from the paper by reading it in to the memory, which itself is part of brain. Whereas in the computer world, CPU does the processing while RAM, also known as Memory acts as the temporary storage area for calculations. I am calling this temporary storage area because, the data will be wiped out when the computer is shutdown or when the power goes down. That’s why people always ask you to save your modifications in a file often. When you save, your file gets written in the hard disk, where the data will remain even if the computer is shut off.
So, remember these three components. CPU, which is often referred as COMPUTE resource in the Cloud Architecture, Memory also known as RAM, and Storage. As we move into cloud, these three components decide the size of the computers that we will rent from those cloud providers thereby influencing the cost of the cloud subscriptions.