03 - Operating Systems & Applications | 05. Operating Systems and Applications Problem Set Flashcards
Describe two fundamental jobs of the operating system.
Our answer
These are the four fundamental jobs of the operating system, you may describe any two in your answer:
The operating system must orchestrate the various processes that are vying for the computer’s limited hardware resources. In its role as process manager, this primarily means controlling which processes get time on the CPU (processor).
The OS must also coordinate how data is stored in memory as well as optimize where data gets stored.
The operating system also takes on the role as file system manager. Our computer has millions of files. These files exist in directories and subdirectories that provide files with some logical ordering. It is the job of the operating system to manage this file system and keep track of which files are where.
The final job of the OS is IO (input/output) management. A computer must be able to interact with external devices like keyboards, mice, microphones, webcams, etc. The operating system provides the connection between these devices and our computer.
How does a file differ from a directory? What is a working directory?
Our answer
A file is a unit of storage used to describe a self-contained piece of data. It creates the basis of the filesystem.
A directory is a data structure that contains references to files and other directories. It is the organizational component of the filesystem, giving it structure.
A working directory is the directory associated with the execution of a process.
Describe each of the following file system concepts:
File attributes
File permissions
File control block
Our answer
File attributes are a collection of metadata that determine how files behave, such as if they are hidden or compressed, while file permissions determine which users and groups can read, write, and execute the file. The file control block contains the accounting information of the file, such as the file’s permissions, owners, size, and the times it was created, modified, and accessed.
How would a request to save a file in an application traverse the layers of the filesystem?
Our answer
The layers of the filesystem from most user facing to closest to the hardware:
Application Programs - This is where the request to save a file begins.
Logical File System - Here the application gets a high-level interface to save the file and verify if the user has permission to modify the file.
File-Organization Module - Finds the software blocks for the file and checks if there is enough space available to save the file.
Basic File System - Schedules the request for the physical hard drive and blocks the request if the resource is busy.
IO Control - Takes the request from the basic file system and transforms it into instructions for the particular storage device the computer is using to save the data.
Devices - Physically changes the magnetic state of the spinning disk in the relevant section as decided by the IO control.
What does it mean for an application to be a cross-platform application?
The defining characteristic of cross-platform applications is that they can be run on multiple operating systems. Cross-platform applications can run on more than one OS, but may not necessarily run on all operating systems.
Describe and provide examples of the three main types of applications discussed in this course.
While there are many different types of applications, the biggest ones (and the ones discussed in this course) are productivity, collaboration, and business applications.
Productivity applications give users the ability to perform daily tasks in a more efficient way. An example of a productivity application is a word processor – consider how much time is saved typing a letter using a word processor rather than handwriting it or using a typewriter.
Collaboration applications allow collections of users to work together (almost always using the internet). These include things like email and video-conferencing apps.
Finally, business applications are apps which perform a specific business function. Here, think of an application that keeps track of a company’s payroll.
What is the difference between downloading and installing a piece of software?
Downloading software is the process by which we obtain the files necessary to install, and ultimately to run a program. Installation is the process of configuring our computer in such a way as to be able to use those files to run the program. For that reason, downloading a piece of software necessarily comes before installing it.
Describe the steps to install a piece of software – from first obtaining the software all the way through using it for the first time.
The very first step to setting up a piece of software is to download it. This means finding a trusted source online and using a download link to retrieve the software. The software will be downloaded in a not-yet-installed but installable form. On a Windows computer, that form is an executable or .exe file. On a Mac, that file can take a couple different forms (most commonly a .pkg file). In either case, simply open the file and you will be prompted to follow a series of steps to install the software. Once the installation is complete, you can now run the software like you would any other application on your computer.
