Computer hardware and software

Every computer is composed of two basic components: hardware and software.

• hardware includes the Physical features, which are every part that you can either see or touch, for example: monitor, case, keyboard, mouse, and printer.
• The part which activates the physical components called software. It includes the features that responsible for directing the work to the hardware. Software can be divided int the programs and data.

von-Neumann architecture of the computer

Von-Neumann computer consists of two main components: memory and CPU. The rest of the computer can be viewed as input/output devices for the two main components. This concept has not yet been overcome and even the latest computers still come from von-Neumann architecture. 

von- Neumann architecture

Application Software

An application software is a computer program designed to perform a group of coordinated functions, tasks, or activities. Examples of an application include a word processor, a spreadsheet, an accounting application, a web browser, a media player or a console game^[1]. Applications may be connected with the computer and its system software or may be published separately, and may be coded as proprietary, open-source or university projects. System software is another type of software that is mainly involved with running the computer, so it consists of low-level programs that interact with the computer at a very basic level, such as operating systems, compilers, and utilities for managing computer resources. When comparing both, applications software sits on top of systems software because it is unable to run without the operating system and system utilities. Application software can also be seen as being either horizontal or vertical. Horizontal applications are more popular and widespread, because they are of general purpose. Vertical applications are niche products, designed for a particular type of business or department within an organization.

Operating System

Operating system is defined as a system software that provide common services for different computer programs and manages computer hardware and software as mentioned before. There are several types of operating systems such as:

Single and multi-tasking- The multi-tasking and single-tasking operating system differs in the number of programs they can run simultaneously. The single tasking system only runs one program at time, whereas the multi-tasking operating system can run two or more programs at the same time.

Single and multi-user- Single-user allows more than one program to run in a tandem^[2], and doesn't have the means to distinguish users.  On the other hand multi-user is able to distinguish different processes and resources of different users and also allows more than one user to interact with the system at the same time.

Distributed- Distributed operating system manages a group of different networked computers that can communicate together to function as one.

There are three features that operating system manage and control, which are:

1.     Process management, code execution, context switching and multitasking.

2.      Memory management, allocation, sharing, and virtual memory.

3.      Device management, input/output, disk access, interrupt handling.

Memory

memory unit is divided to two types of register: MDR-The register of a computer's control unit that has the data to be stored in the computer storage e.g. RAM. MAR-has both memory address of data and memory address of instructions. The function of this specific register is to access data and instructions from the memory.

Processing unit- composed of a units which process the orders. One of them is the ALU-arithmetic logical unit that prefoemes two typed of orders: 1. Mathematical operations (+,-) 2. Logical operations (=,<,>)

Control unit- Unit that bring the instruction from memory to be executed and decodes. CPU- central processing unit. Has the instructions of a computer program by presenting the basic arithmetic, logical, control and input/output. CPU composed of ALU (arithmetic logical unit) and CU (control unit). Output unit- Hardware which performs the result of the instruction.

RAM

Is random acsses memory, keeps the data and general purpose program that the compter executes. RAM is not permanent, its contain can be changed and it is erased when the computer is off.

Storing device

any hardware that can hold information, temporarily or permanently. we distinguish two types of storage: a primary storage device (RAM), and a secondary storage device (hard drive). Secondary storage can be removable, internal, or external storage.

Examples of computer storage: 1. Magnetic storage deviced- for example: hard drive, floppy diskette etc. 2. Optical- example: blu-ray disc, CD-rom disc etc. 3. Flash memory devices- memory card,memory stick. 4. Online and cloud- cloud storage, network media. 5. Paper storage- OMR, punch card. Today the most storage devices are hard disc drive or SSD.

motherboard

is the physical arrangement in a computer that contains the computer's basic circuitry and components. It has a socket for the CPU, RAM and expansion part (sound cards, graphic cards ETC) and also connects together the CPU, memory, hard drives, optical drives, video card and more. To activate a computer there Is a need in an operating system. (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. All computer programs require an operating system to function. Operating system controls computer's hardware, run the computer's programs and orgenizes files. The programs that we use on everyday base called an application program. app is a computer program designed to perform a group of coordinated functions, tasks, or activities for the benefit of the user. E.g. ppt, excel, word.

Bits and bytes

Bits- are the smallest storage units in the computer. A bit can store just 0 or 1, which is called binary, and therefore can be stored by physical devices or systems that has two separate states. For example 2 positions, or states of an electrical switch, the two states being ‘on‘ and ‘off‘. A bit can also be described as true/ false, no/ yes etc. Notice that a bit has only two coding options, or 2 values. One bit is too small to be used, and thus computers use a larger storage unit called bytes. Bytes- are made of bits. 8 bits are used to create 1 byte. 1 byte can store 1 letter, character or symbol, such as the letter ‘a‘, the number ‘6‘ or the symbol ‘@‘, meaning 1 byte has only 1 possible value. The letter ‘a‘ for example, is one byte, which is made by the combination of 01000001, and each number is 1 bit. RAM, hard drives and flash drives, are all types of storages measured by bytes. Other storage units: 1 KB (kilobytes)= 1024 bytes 1 MB (megabytes)= 1024 KB 1 GB (gigabyte)= 1024 MB 1 TB (terabyte)= 1024 GB 1 PB (petabyte)= 1024 TB Each storage unit is made of the smaller units, and the basic one composing all is the bit.

data

is any set of characters that has been gathered and translated for some purpose, usually analysis. It can be any character, including text and numbers, pictures, sound, or video. If data is not put into context, it doesn't do anything to a human or computer. Within a computer's storage, data is a collection of numbers represented as bytes that are in turn composed of bits (binary digits) that can have the value one or zero. Data is processed by the CPU, which uses logical operations to produce new data (output) from source data (input).

Information

can be encoded into various forms for transmission and interpretation (for example, information may be encoded into a sequence of signs, or transmitted via a sequence of signals). The bit is a typical unit of information, but other units such as the nat may be used. Example: information in one "fair" coin flip: log2(2/1) = 1 bit, and in two fair coin flips is log2(4/1) = 2 bits.

Knowledge

is a familiarity, awareness or understanding of someone or something, such as facts, information, descriptions or skills, which is acquired through experience or education by perceiving, discovering, or learning. Knowledge can refer to a theoretical or practical understanding of a subject.

algorithm

An algorithm (pronounced AL-go-rith-um) is a procedure or formula for solving a problem, based on conducting a sequence of specified actions. A computer program can be viewed as an elaborate algorithm. In mathematics and computer science, an algorithm usually means a small procedure that solves a recurrent problem.

references

1.    "Application software". PC Magazine. Ziff Davis.

2.    Lorch, Jacob R., and Alan Jay Smith. "Reducing processor power consumption by improving processor time management in a single-user operating system."

links

bibliography

http://www.computerhope.com http://whatis.techtarget.com/definition/algorithm http://www.merriam-webster.com https://web.stanford.edu/class/cs101/bits-bytes.html