Operating Systems Terminology’s – Operating Systems

Operating Systems Terminology’s

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Processes: A process is an instance of a program running in a computer.
A program in the execution is called a Process. Process is not the same as program. A process is more than a program code (Program Code + Data + Execution status).

Files: A collection of data or information that has a name, called the filename. Almost all information stored in a computer must be in a file. There are many different types of files: data files, text files , program files, directory files, and so on. Different types of files store different types of information. For example, program files store programs, whereas text files store text.

A system call is a way for programs to interact with the operating system. A computer program makes a system call when it makes a request to the operating system’s kernel. System calls are used for hardware services, to create or execute a process, and for communicating with kernel services, including application and process scheduling.

Shell AND kernel
A shell is a software interface that’s often a command line interface that enables the user to interact with the computer. Some examples of shells are MS-DOS Shell, command.com, csh, ksh, and sh. Below is a picture and example of what a Terminal window with an open shell.
A Kernel is first section of the operating system to load into memory. As the center of the operating system, the kernel needs to be small, efficient and loaded into a protected area in the memory; so as not to be overwritten. It can be responsible for such things as disk drive management, interrupt handler, file management, memory management, process management, etc.

Virtual Machines: A virtual machine (VM) is a software program or operating system that not only exhibits the behavior of a separate computer, but is also capable of performing tasks such as running applications and programs like a separate computer. A virtual machine, usually known as a guest is created within another computing environment referred as a “host.” Multiple virtual machines can exist within a single host at one time.