ICT Lessons

Hardware and Software

 A computer system consists  of two major elements: hardware and software.

Computer hardware is the collection of all the parts you can physically touch.

 Computer software, on the other hand, is not something you can touch. Software is a set of instructions for a computer to perform specific operations. You need both hardware and software for a computer system to work.

· Some hardware components are easy to recognize, such as the computer case, keyboard, and monitor. However, there are many different types of hardware components. In this lesson, you will learn how to recognize the different components and what they do.

Software
“Software is the programs or instructions that run a computer system. Software works with hardware in that software provides the instructions and hardware actually carries out the work".(Wilson.C, (2001) Software Design and Development: The Preliminary Course.)
Software is the set of instructions used to direct the operation of the hardware causing it to solve some problem. Software is the communication link between hardware and users. There are two main types of software present in all computer systems; system software and application software

Relationship between hardware and software

Software and Hardware work together to process the input.  The CPU (Central Processing Unit) processes input into output through the fetch-execute cycle. 
The CPU is made up of several different parts including: Arithmetic and Logic Unit (ALU), Control Unit (CU) and various registers. Its performance is measured in GHz or Petaflops(speed) and word size (power), for example Pentium4 2.4 GHz 32 bit Quad Core.

· The Arithmetic and Logic Unit performs calculations

· The Control Unit loads and executes instructions

· The current instruction is stored in the Instruction Register

The other Registers store the results of calculations (Accumulator) and where the next instruction is to come from (Program Counter)

· Communications between the CPU and memory occur using Buses - Address Bus, Data Bus, and the Control Bus

· Primary and secondary storage
There are typically two types of storage used in computers - primary and secondary. Both memory types are physical devices inside the computer. Upgrading them requires the purchase of more hardware. 

Secondary storage · holds anything permanent · stores programmed instructions the most common instructions required (new, close, exit, etc) and transfers to RAM when necessary · does not need a constant flow of electricity to keep data (can be turned off without risk) · typically referred to as the hard disk or solid state drive · external and independent from the Central Processing Unit v Primary storage · used to hold and store only the data that is needed at the moment · requires a constant flow of electricity to operate  · volatile memory - all data is lost when turned off · typically referred to as RAM or Random Access Memory · key component of operation of the Central processing unit

To process data, the CPU performs a cycle of events on a single instruction. This is called the fetch-execute cycle or machine cycle.

· Fetch: The instruction is retrieved from memory and decoded in the control section. The address bus conveys the address to the memory controller that selects the cell address in memory containing the instructions

· Decode: The instruction at the address is sent on the data bus to the decoder where it is decoded into an opcode (is the instructions for processing the data) and an operand (data which needs to be processed). The opcode is sent to the ALU (Arithmetic Logic Unit). The operand goes on the address bus to the memory controller that retrieves the data from the memory cell. This data is sent on the data bus.

· Execute: The processing section carries out the decoded instruction, sending data to or from memory as needed.

· Store: The result of the ALU's calculation is stored in the accumulator

RELEVANCE OF THE LECTURE TO TEACHERS.

The lecture presented is relevant to me as a teacher since help me to be aware about computer hardware and computer software,  computer soft ware and hardware  also help me to be aware about application of the computer system in daily life. also sharing of  data, network and files by the use of a computer network

SAMPLE QUESTION DEVELOPED AFTER THE LECTURE.

As a teacher after the lecture, I developed some questions on the knowledge of computer hardware and software.

· Why computer hardware and software become important field of study?

· What are computer storage devices and its application?

· What type of computer used for network sharing