Operating system

An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. All computer programs, excluding firmware, require an operating system to function.

explain the role of an operating system

Task	What is the role of the OS?
Managing memory	The memory management function keeps track of the status of each memory location, either allocated or free. It determines how memory is allocated among competing processes, deciding which gets memory, when they receive it, and how much they are allowed. An operating system must also keep track of programs in memory.
Manage peripherals	Usually OS manages peripherals via a device driver: handles the translation of requests between a device and the computer defines where a process must put outgoing data before it can be sent, and where incoming messages will be stored when they are received wakes up the device when it is needed and put it back to sleep when it is not
Manage hardware interfaces	This is related to peripherals, above. A hardware interface is the wires, plugs and sockets that hardware devices use to communicate with each other.
Allocating storage	This is not only reading, storing and writing data to a disk, but
Swapping between programs on time-slicing	With a multi-user system, a time-slice is the set amount of processing time each user gets. With a single-user system, a time-slice is the set amount of processing time each program gets. Slices (also called threads) are alternately processed to give the illusion of many tasks happening at once

Different operating systems

1. Linux
2. OS X
3. WIndows
4. iOS
5. Android OS
6. Google chrome OS (Based on Linux)

Linux tools to view internal management of resources

An operating system also provides tools for managing the operating system. These are often called utilities or system tools. Click here for a brilliant graphic showing the different types of tools you can use to view inside the Linux operating system. These tools give you insight and information for how the operating system is managing different resources. Below is a table with resources and tools to help you view how the OS is managing a particular resource.

Resource	Linux tools you can use to understand what is going on
Memory	top, htop, free, vmstat
Processes	top
Files	File system, df, du, mount, lsof
Security	fstab
CPU Scheduling	perf
Devices, Device I/O	iotop, iostat
Interrupts	perf
The user interface, most often a GUI but also a CLI	we dont really monitor this
Networks	netstat, top, tcpdump, iptraf, iftop, nmon

Do you understand this topic?

• Describe the main functions of an operating system.

Do you have an advanced understanding about this topic?

• Describe how an operating system manages the functions you have just described above.

Standards

• I can explain the role of the operating system in terms of managing memory, peripherals and hardware interfaces.

Give a detailed account including reasons or causes.

a group or system of interconnected people or things.

Give a detailed account or picture of a situation, event, pattern or process.