Basics of Computer

1. Block diagram of computer

Mainly computer system consists of three parts:
i) Central processing unit(CPU)
ii) Input Devices
iii) Output Devices

A large amount of data is stored in the computer memory with the help of primary and secondary storage devices.

Input Devices

The user provides the set of instruction or information to the computer system with the help of input devices such as the keyboard, mouse, scanner, etc. The data representation to the computer system is in the form of binary language after that the processor processes the converted data. The input unit implements the data which is instructed by the user to the system.

Output Devices

The output devices produce or generate the desired result according to our input,

such as a printer, monitor, etc. These devices convert the data into a human-readable form from binary code.

Central Processing Unit (CPU)

The CPU is like the heart/brain of the computer. The user does not get the desired output, without the necessary option taken by the CPU. The Central processing unit (CPU) is responsible for the processing of all the instructions which are given by the user to the computer system.

The CPU contains two parts: the arithmetic logic unit (ALU) and control unit (CU).

i) Control Unit

The control unit (CU) controls all the activities or operations which are performed inside the  computer system. It receives instructions or information directly from the main memory of the computer.

When the control unit receives an instruction set or information, it converts the instruction set to control signals then; these signals are sent to the central processor for further processing. The control unit understands which operation to execute, accurately, and in which order.

ii) Arithmetic and Logical Unit

The arithmetic and logical unit is the combinational digital electronic circuit that can perform arithmetic operations on integer binary numbers. It presents the arithmetic and logical operation. The basic arithmetic and bitwise logic functions are supported by ALU.

Memory

i) Main Memory

The Random Access Memory is the main memory of the computer system, which is known as RAM. The main memory can store the operating system software, application software, and other information. The Ram is one of the fastest memories, and it allows the data to be readable and writable.

ii) Secondary Memory

We can store the data and programs on a long-term basis in the secondary memory. The hard disks and the optical disks are the common secondary devices. It is slow and cheap memory as compare to primary memory. This memory is not connected to the processor directly. It has a large capacity to store the data. The hard disk has a capacity of 500 gigabytes.

2. What are the differences between hardware and software?

Basis of Differentiation	Hardware	Software
Definition	Hardware refers to physical components and physical devices that are necessary for storing and executing (or running) the software. They serve as a delivery system for the set of instructions provided by the software.	Software refers to a collection of programs, documentation, codes, instructions, etc. That enables users to interact with computer systems. Software is typically a program that’s essential for computers to perform specific tasks.
Types	The different types of hardware comprised of input and storage devices, processing units, control devices, and output components.	Programming software, System software, and Application software are the different types of software available for users.
Examples	CD-ROM, display monitor, sound card, printer, video card, scanner, label maker, router, modem, etc.	Examples of Software such as Adobe Acrobat, QuickBooks, Google Chrome Microsoft Excel, Microsoft Word, Apple Maps, etc.
Nature	Hardware is tangible and physical.	Software is non-tangible and logical.
Wear and tear	Hardware depreciates in performance and wears out over time.	Software remains the way it is and does not wear out over time. However, it is common for bugs to appear in software.
Virus attacks	Hardware cannot be impacted by viral attacks directly.	Viral attacks with use can impact software programs and applications.

3. Difference between System Software and Application Software?

System Software	Application Software
System software is used for operating computer hardware.	Application software is used by user to perform specific task.
System softwares are installed on the computer when operating system is installed.	Application softwares are installed according to user’s requirements.
In general, the user does not interact with system software because it works in the background.	In general, the user interacts with application sofwares.
System software can run independently. It provides platform for running application softwares.	Application software can’t run independently. They can’t run without the presence of system software.
Some examples of system softwares are compiler, assembler, debugger, driver, etc.	Some examples of application softwares are word processor, web browser, media player, etc.

4. Difference between Compiler and Interpreter?

BASIS FOR COMPARISON	COMPILER	INTERPRETER
Input	It takes an entire program at a time.	It takes a single line of code or instruction at a time.
Output	It generates intermediate object code.	It takes a single line of code or instruction at a time.
Working mechanism	The compilation is done before execution.	It takes a single line of code or instruction at a time.
Speed	Comparatively faster	Slower
Memory	Memory requirement is more due to the creation of object code.	It requires less memory as it does not create intermediate object code.
Errors	Display all errors after compilation, all at the same time.	Displays error of each line one by one.
Error detection	Difficult	Easier comparatively
Pertaining Programming languages	C, C++, C#, Scala, typescript uses compiler.	PHP, Perl, Python, Ruby uses an interpreter.

5. Types of Computer Languages.

Low Level Computer Languages

These are machine codes or close to it. Computer cannot understand instruction given in high level languages or in English. It can only understand and execute instructions given in the form of machine languages i.e. the binary number 0 and 1.

There are two types of low level computer language.

Machine Language

The lowest and most elementary language and was the first type of programming language to be developed. Mache language is basically the only language which computer can understand. In fact, a manufacturer designs a computer to obey just one language, its machine code, which is represented inside the computer by a string of binary digits (bits) 0 and 1. The symbol 0 stands for the absence of an electric pulse and 1 for the presence of an electric pulse.

Assembly Languages

It was developed to overcome some of the many inconveniences of machine language. This is another low level but a very important language in which operation codes and operands are given in the form of alphanumeric symbols instead of 0’s and 1’s. These alphanumeric symbols will be known as mnemonic codes and can have maximum up to 5 letter combinations e.g. ADD for addition, SUB for subtraction, START LABEL etc. because of this feature it is also known as “Symbolic Programming Language”. This language is very difficult and needs a lot of practice to master it because very small English support is given.

Computer High Level Languages

High level computer languages give formats close to English and the purpose of developing high level languages is to enable people to write programs easily and in their own native language environment (English). High-level languages are basically symbolic languages that use English words and/or mathematical symbols rather than mnemonic codes. Each instruction in the high level language is translated into many machine language instructions thus showing one-to-many translation.

Problem-Oriented Language: These are languages used for handling specialized types of data processing problems where programmer only specifies the input/output requirements and other relative information of the problem, that are to be solved. The programmer does not have to specify the procedure to be followed in solving that particular problem.

Procedural Language: These are general purpose languages that are designed to express the logic of a data processing problem.

Non-procedural Language: Computer Programming Languages that allow users and professional programmers to specify the results they want without specifying how to solve the problem.

6. Difference Between Volatile Memory and Non-Volatile Memory.

BASIS FOR COMPARISON	VOLATILE MEMORY	NON-VOLATILE MEMORY
Definition	Volatile Memory is the type of computer memory that is temporary in nature. It stores the data inside it only until the power is supplied.	Non-Volatile Memory is the type of computer memory that is permanent in nature. The data stored in such kind of memory remains there even after the system is turned off.
Data Stored	Volatile memory store data of the programs that are currently in process by the CPU. Frequently used data and information about the process is stored in Volatile memory.	Non-volatile memory store data of the basic booting process of the computer system BIOS. All kind of media and data that has to be saved permanently or for the longer period.
Effects	Volatile Memory has effects on the system’s performance. The more storage space on the volatile memory such as RAM and cache, the more efficient will be the performance of the system.	Non-Volatile Memory has effects on the system storage. The more storage space, the more amounts of data can be stored in the computer system and can be stored permanently.
Speed	Volatile memories are the fastest memories in nature.	Non- Volatiles memories whereas are relatively slow as compare to volatile memories.
Example	Common Examples of volatile memory includes the RAM of the computer, Cache, etc.	Common Examples of the Non-volatile memory includes ROM ( Secondary Storage, Hard disc) of the computer, optical storage discs, flash memory, etc.

7. Why C is called middle level language?

C is called middle-level language because it actually binds the gap between a machine level language and high-level languages. A user can use c language to do System Programming (for writing operating system) as well as Application Programming (for generating menu driven customer billing system ). That's why it is called the middle-level language.