TOPIC 1: Introduction To Computers
A Computer is an electronic device in which text, sound, images, animations, and video used as input are called data, and all numbers, text, sound, images, animations, and video returned as output are called information.
The data consists of numbers, text, sound, images and video. The process converts numbers, text, sound, images and video (data) into usable data, which is called information.The information consists of numbers, text, sound, images and video that has been converted by the process
The data is inserted using an input device.The central processing unit (CPU) converts data to information.The information is displayed using an output device.
A storage device is used for storing data and information.
A basic computer comprises of 4 components: an input device , a CPU, output devices, and memory.
TOPIC 2: Operating Systems
A computer system has many resources (hardware and software), which are always required to perform and complete a specific task. The commonly needed resources are input/output devices, memory, file storage space, CPU etc. The operating system behaves as a manager of the above resources. It allocates them to specific programs and users as necessary for their task. Thus,operating system works as a resource manager.
Operating systems (OS) provide an important interface between a computer's hardware and the applications that run on it. It also makes sure that the computer's resources such as its CPU, hard disk, and memory, are appropriately utilized.
Types Of Operating Systems
- UNIX is an operating system whose development dates back to the 1960s
- It is a multi-user, multi-tasking system for servers, desktops and laptops.
- UNIX systems also have a graphical user interface (GUI) similar to Microsoft Windows which provides a user friendly environment.
- The various varieties of UNIX are Sun Solaris, GNU/Linux.
- The UNIX operating system comprises of three parts; the kernel, the shell and the programs.
- Linux is a free software and open source development OS which means that all underlying source code can be freely modified, used, and redistributed by anyone.
- The name “Linux” comes from the Linux kernel which was started in 1991 by Linus Torvalds.
- Linux is most importantly known for its use in servers.
- It is basically an operating system used in a variety of computer hardware, supercomputers and devices such as mobile phones and routers.
- It is an advanced operating system, developed by Microsoft Corporation.
- It is an improvised version of Windows 3x, 9x and replacement of DOS.
- It is not an open source operating system.
- It is not available free of cost.
- It is one of the most famous operating system which is incorporated in PC's and Laptops.
TOPIC 3:Software Development Life Cycle (SDLC)
SDLC, Software Development Life Cycle is a process used by software industry to design, develop,implement and test high quality softwares. The SDLC aims to develop a high quality software that meets or exceeds customer expectations, reaches completion within times and cost estimates.It involves 6 stages which are as follows:
Stages Of SDLC
It is the fundamental stage in SDLC. It is implemented by the senior members of the team by obtaining inputs from the customer,the department of sales and domain experts from the industry. This data is then used to plan the basic project approach.
The next step is to define and document the requirements of the product and get them approved from the customer.
The design approach for the product architecture is proposed and documented in a DDS - Design Document Specification. This DDS is reviewed by all the crucial stakeholders and based on different parameters such as risk assessment, product robustness, budget and time constraints and the appropriate approach is selected for the product.
In this stage of SDLC ,the practical development starts and the product is built.The code is generated as per DDS during this stage. The preferable programming language is chosen with respect to the type of software being developed.
This stage is usually a subset of all the stages, the testing activities are mostly involved in all the stages of SDLC. This stage basically refers to the testing only stage of the product where products defects are reported,fixed and retested.
Once the product is tested and ready to be deployed it is released formally in the market.Next>>>>