COMPUTER is derived from the word “Compute“, which means calculating something. So, in general, a Computer is an electronic device/machine which receives some input, process the data, and provides information in the desired format.

Computer Structure
The above diagram reflects the basic structure and work-flow of a Computer. It also, shows that the CPU is the brain of the computer, which decides how to handle input and output devices.
Data and Information
Data is a collection of lots of content in the form of Numbers, characters, images, etc. On the other hand, identifying and extracting only that data which is useful for us is known as Information.
In simple, Information is a processed version of the Data.
Input Devices
Input devices like Keyboard, Mouse, Touch screen are used to give inputs or feed data into the computer system.
Output Devices
Output devices like Monitor display, Speaker, Printer, etc. are used to get information after processing.
CPU (Central Processing Unit)
CPU is the brain of the computers. It provides a connection between Input devices, Output devices and Memory of the computer. All these components remain connected via Motherboard.

A Motherboard is a chip-set to connect all these components and also, help for intercommunication. Below are the different Units embedded within a standard CPU:
MU (Memory Unit)
It controls all types of memory in a computer. There are mainly three types of Memory.
HDD (Hard Disk Drive) or Permanent Memory
Basically, HDD stores all the data including Operating System, Installed Software, Applications, Files, Folders, etc. Size of this type of memory would remain in GB(Gigabytes) and TB(Terabytes).
RAM (Random Access Memory)
As we know, HDD stores all the data in memory. But at run-time, we need only a few files or application for the processing. RAM is used to access these type of files from the HDD to increase the speed and performance.
To understand the difference between HDD and RAM, take a simple example. Suppose you have a table with a drawer. Consider, the drawer is like an HDD which contains lots of files. If we want to work on a specific file, we need to pull out that file and put the same on the table to open and work in it. So this table would be like RAM. You can open multiple files on the table till it has space, after that you have to free up space by closing the files.
ROM (Read Only Memory)
The above memories HDD and RAM would be active and available only when the system is ON and logged in by the user. But you know, when we start the computer there is another type of memory which has been used to boot and reboot the system.
Booting is a process of loading the operating system and all the required application in the memory for the user. After Booting, the first program that runs is called BIOS (Basic Input Output System).
- Cold Booting: When the system is started first time by Switching ON, is called cold booting, after that BIOS runs.
- Warm Booting: When the system is already running and needs to re-started, called warm booting. In this case, BIOS is not reloaded.
ALU (Arithmetic and Logical Unit)
This unit performs all the processing work. It takes the input from the Control Unit, performs all types of calculation, validation and decision work and sends the output to the Control Unit.
CU (Control Unit)
Control Unit, identifies the input and output devices. It takes input from the user in the form of the Data. Share this data with ALU for processing. After that sends this data to the Output device so that the user can view the output.
Related Links:
- Computer Basics -1 || Introduction and Structure of Computer.
- Computer Basics -2 || Types of Computers and Usage.
- Computer Basics -3 || What are the different types of Software?
- Computer Basics -4 || Importance of Operating System(OS).
- Computer Basics -5 || Understanding of Number System.
- Computer Basics -6 || Understanding MS-DOS Commands.
- Computer Basics -7 || Important Features of MS-Word.
- Computer Basics -8 || Let’s learn the usage of MS-Excel.
- Computer Basics -9 || Understand and Implement Data Validation in Excel.
- Computer Basics -10 || How to apply Filter in a data set in Excel?
- Computer Basics -11 || Using Charts in place of Data Tables in Excel.
- Computer Basics -12 || Advantages of PivotCharts over Simple Charts in Excel.
- Computer Basics -13 || Creating pivot charts/tables in Excel.
- Abbreviations to Full-Forms in Computer Basics.
TestNG:
- TestNG – 1 || Introduction and benefits of TestNG Framework.
- TestNG – 2 || Installation process and a sample program of TestNG.
- TestNG – 3 || Create and execute multiple Test Cases.
- TestNG – 4 || Let’s understand @Test Annotation and attributes.
- TestNG – 5 || Understand Assertion in TestNG.
- TestNG – 6 || Use of @BeforeMethod and @AfterMethod.
- TestNG – 7 || Use of @BeforeClass and @AfterClass.
- TestNG – 8 || Creation and execution of Test Suites.
- TestNG – 9 || Let’s move deep into the Test Suites.
- TestNG – 10 || Use @BeforeTest and @AfterTest Annotations.
- TestNG – 11 || Groups attribute with @Test Annotation.
- TestNG – 12 || Use of @BeforeGroups & @AfterGroups.
- TestNG – 13 || Use of @BeforeSuite & @AfterSuite.
- TestNG – 14 || DataProvider annotation & attribute.
- TestNG – 15 || DataProvider with parameters.
- TestNG – 16 || Access data from Excel sheet using DataProvider.
- TestNG – 17 || Passing multiple Parameters in testng xml.
- TestNG – 18 || Multiple Browser and Parallel Execution in TestNG.
- TestNG -19 || Concept of Parallel Execution.
- TestNG – 20 || Run TestNG Program using main() method.
Java Basics:
- Basic Java – 1 || Understand Java before start learning JAVA.
- Basic Java – 2 || Variables and Data Types used in JAVA.
- Basic Java – 3 || Understanding Class, Objects, Methods in Java.
- Basic Java – 4 || More on methods(Return Type and Parameters)
- Basic Java – 5 || Methods- Call by Value and Call by Reference in Java.
- Basic Java – 6 || Understanding of Constructor and Destructor in JAVA.
- Basic Java – 7 || Static Variables and Methods.
- Basic Java – 8 || Lets learn about Arrays in Java.
- Basic Java – 9 || Performing multiple operations using Java Operators.
- Basic Java – 10 || Conditions (If and Switch) in JAVA.
- Basic Java – 11 || for and for-each in Java. (Loops Part-1)
- Basic Java – 12 || Alternate looping concepts while and do-while. (Loops Part-2)
- Basic Java – 13 || Decimal values v/s Octal base(8) values in JAVA.
- Basic Java – 14 || Learn about String literals in Java.
- Basic Java – 15 || Runtime User Input using Scanner Class (Part-1).
- Basic Java – 16 || Runtime User Input using BufferedReader Class (Part-2).
- Basic Java – 17 || Runtime User Input using Console Class (Part-3).
- Basic Java – 18 || Difference between break and continue keywords.
- Basic Java – 19 || Sending Email using Java (Part-1).
- Basic Java – 20 || Sending Email with attachment using Java (Part-2).
- Basic Java – 21 || Stack memory and Heap memory in Java.
- Basic Java – 22 || Let’s learn more about String.
- Basic Java – 23 || String, StringBuffer & StringBuilder in Java.
- Basic Java – 24 || Exception Handling using Try Catch.
- File Handling | Reading data from word document(.doc or .docx) in JAVA.
- File Handling | Reading data from Excel files (.xls or .xlsx) using JAVA.
- File Handling | Writing data into an Excel(.XLSX or .XLS) File.
- File Handling | Implement formatting in Excel using Java.
- File Handling | Copy existing data from one workbook to another workbook in Java.
- File Handling | Reading data from PDF file using JAVA.
- File Handling || Traverse folders and subfolders in Java.
- File Handling || Reading and Writing data from a text file.
- File Handling || Multiple file creation using template based input data.
- Framework || Simple example of Key Driven Framework using excel sheet in Selenium(JAVA).
- QnA || How to use Constructors in Abstract class?
- QnA | Difference between Integer and int keywords.
- QnA | Can main method be overloaded?
- QnA | How do I reverse a String/Sentence in Java?
- QnA | Perform Multiplication and Division without * or / or % operators.
- QnA | How do I get the default value of data type?
- QnA | How to split String if it contains period symbol (.) in between?
- Different ways to Reverse a String in Java.
- Copy formatting & style of cells from one sheet to another.
- Getting IP address and Hostname using InetAddress Class.
- User inputs via Command Prompt using arguments of main() method of a class.
- Program for List and ArrayList in Java.
- Useful methods and implementation under Scanner Class.
- Swapping two variable values without using any third variable.
- Difference between int x= 10 and y=010 in Java.
- Parameterized Constructors v/s Setter and Getter function in JAVA.
- Override a Static Method.
- Computer Basics -13 || Creating pivot charts/tables in Excel.
- Computer Basics -12 || Advantages of PivotCharts over Simple Charts in Excel.
- Computer Basics -11 || Using Charts in place of Data Tables in Excel.
- Computer Basics -10 || How to apply Filter in a data set in Excel?
- Computer Basics -9 || Understand and Implement Data Validation in Excel.
- Computer Basics -8 || Let’s learn the usage of MS-Excel.