Lecture 2-Information Systems (II).pdf

Information Systems (II) LECTURE 2 Operating Systems What is an Operating System? ▪ An operating system is a software which acts as an interface between the end user and computer hardware. ▪ Every computer must have at least one OS to run other programs. An application like Chrome, MS Word, Game...

Information Systems (II) LECTURE 2 Operating Systems What is an Operating System? ▪ An operating system is a software which acts as an interface between the end user and computer hardware. ▪ Every computer must have at least one OS to run other programs. An application like Chrome, MS Word, Games, etc needs some environment in which it will run and perform its task. ▪ The OS helps you to communicate with the computer without knowing how to speak the computer's language. It is not possible for the user to use any computer or mobile device without having an operating system. Examples of OS with Market Share History Of OS ▪Operating systems were first developed in the late 1950s to manage tape storage ▪The General Motors Research Lab implemented the first OS in the early 1950s for their IBM 701 ▪In the mid-1960s, operating systems started to use disks ▪In the late 1960s, the first version of the Unix OS was developed ▪The first OS built by Microsoft was DOS. It was built in 1981 by purchasing the 86-DOS software from a Seattle company ▪The present-day popular OS Windows first came to existence in 1985 when a GUI was created and paired with MS-DOS. Features of Operating System ▪Protected and supervisor mode ▪Allows disk access and file systems Device drivers Networking Security ▪Program Execution ▪Memory management Virtual Memory Multitasking ▪Handling I/O operations ▪Manipulation of the file system ▪Error Detection and handling ▪Resource allocation ▪Information and Resource Protection Functions of an Operating System Functions of an Operating System ▪Process management: Process management helps OS to create and delete processes. It also provides mechanisms for synchronization and communication among processes. ▪Memory management: Memory management module performs the task of allocation and deallocation of memory space to programs in need of this resources. ▪File management: It manages all the file-related activities such as organization storage, retrieval, naming, sharing, and protection of files. ▪Device Management: Device management keeps tracks of all devices. This module also responsible for this task is known as the I/O controller. It also performs the task of allocation and deallocation of the devices. ▪I/O System Management: One of the main objects of any OS is to hide the peculiarities of that hardware devices from the user. Functions of an Operating System ▪ Secondary-Storage Management: Systems have several levels of storage which includes primary storage, secondary storage, and cache storage. Instructions and data must be stored in primary storage or cache so that a running program can reference it. ▪ Security: Security module protects the data and information of a computer system against malware threat and unauthorized access. ▪ Command interpretation: This module is interpreting commands given by the and acting system resources to process that commands. ▪ Networking: A distributed system is a group of processors which do not share memory, hardware devices, or a clock. The processors communicate with one another through the network. ▪ Job accounting: Keeping track of time & resource used by various job and users. ▪ Communication management: Coordination and assignment of compilers, interpreters, and another software resource of the various users of the computer systems Types of Operating system ▪Batch Operating System ▪Multitasking/Time Sharing OS ▪Multiprocessing OS ▪Real Time OS ▪Distributed OS ▪Network OS ▪Mobile OS Types of Operating system Batch Operating System ▪Some computer processes are very lengthy and time-consuming. To speed the same process, a job with a similar type of needs are batched together and run as a group. ▪The user of a batch operating system never directly interacts with the computer. In this type of OS, every user prepares his or her job on an offline device like a punch card and submit it to the computer operator. Types of Operating system Multi-Tasking/Time-sharing Operating systems Time-sharing operating system enables people located at a different terminal(shell) to use a single computer system at the same time. The processor time (CPU) which is shared among multiple users is termed as time sharing. Real time OS A real time operating system time interval to process and respond to inputs is very small. Examples: Military Software Systems, Space Software Systems. Distributed Operating System Distributed systems use many processors located in different machines to provide very fast computation to its users. Types of Operating system Network Operating System Network Operating System runs on a server. It provides the capability to serve to manage data, user, groups, security, application, and other networking functions. Mobile OS Mobile operating systems are those OS which is especially that are designed to power smartphones, tablets, and wearables devices. Some most famous mobile operating systems are Android and iOS, but others include BlackBerry, Web, and watchOS. The advantage of using Operating System ▪Allows you to hide details of hardware by creating an abstraction ▪Easy to use with a GUI ▪Offers an environment in which a user may execute programs/applications ▪The operating system must make sure that the computer system convenient to use ▪Operating System acts as an intermediary among applications and the hardware components ▪It provides the computer system resources with easy to use format ▪Acts as an intermediary between all hardware and software of the system Cloud Computing Cloud Computing What is cloud? “The cloud” refers to applications, services, and data storage on the Internet. Examples: E-mail, Google drive, One drive, Salesforce (CRM) 18 Advantages of Cloud Computing ▪No software to install or upgrades to maintain. ▪Available from any computer that has access to the Internet. ▪Can scale to a large number of users easily. ▪New applications can be up and running very quickly. ▪Services can be leased for a limited time on an as-needed basis. ▪Your information is not lost if your hard disk crashes or your laptop is stolen. ▪You are not limited by the available memory or disk space on your computer. Disadvantages of Cloud Computing ▪Your information is stored on someone else’s computer – how safe is it? ▪You must have Internet access to use it. If you do not have access, you’re out of luck. ▪You are relying on a third-party to provide these services. 20 Using a Private Cloud ▪Many organizations are understandably nervous about giving up control of their data and some of their applications by using cloud computing. ▪But they also see the value in reducing the need for installing software and adding disk storage to local computers. ▪A solution to this problem lies in the concept of a private cloud. ▪While there are various models of a private cloud, the basic idea is for the cloud service provider to section off web server space for a specific organization. ▪The organization has full control over that server space while still gaining some of the benefits of cloud computing. Computer Network Computer Network ▪A computer network is a system in which multiple computers are connected to each other to share information and resources. ▪Characteristics of a computer network ◦ Share Resources from one computer to another ◦ Create files and store them in one computer, access those files from the other computer(s) connected over the network ◦ Connect a printer, scanner, or a fax machine to one computer within the network and let other computers of the network use the machines available over network. 23 What are the different computer network topologies? Organizational Networking 25 Computer Applications in Society ▪What are some examples of computer applications in society? ◦ Education ◦ Finance ◦ Government ◦ Health Care ◦ Science ◦ Publishing ◦ Travel ◦ Manufacturing DOC 314 DIGITAL SKILLS FOR HIGHER EDUCATION 26