Plat Tech

prelims

Platform Technologies

an extensible hardware and software architecture providing core infrastructural services, abstraction layers, and modular interfaces that allows developers to build and run independent applications.

Operating Systems

System software like Microsoft Windows or Linux that manages computer hardware and system resources.

Computing Platforms

Cloud and virtualized environments providing raw processing power and execution runtimes.

Database Platform

Systems like MySQL or MongoDB used to organize, store, and retrieve structured and unstructured data.

Storage Platform

Scalable object and file storage systems featuring resilient, multi-location backups.

OPERATING SYSTEM

• It is the main software that runs a computer.

• acts as a bridge between you and the machine hardware.

PROCESS

It is basically a program that is currently running.

PROCESS STATES

a process moves through five primary states during its lifecycle

New

being created

Ready

waiting for CPU time

Running

executing instructions

Waiting/Blocked

waiting for an event or I/O

Terminated

finished execution

THREAD

is a unit of execution within a process.

CPU Scheduling

It is an operating system method that picks processes from the ready queue and assigns them to the CPU to maximize use, speed up response, and handle multitasking.

Core Components of an Operating System

1. Kernel

2. Process Scheduler

3. Memory Manager

4. File System

5. Device Drivers

6. User Interface

Main Hardware Managed by an Operating System

1. CPU

2. RAM

3. Storage Devices (HDD/SSD)

4. Motherboard

5. GPU (Graphical Processing Unit)

6. I/O Devices

Device Drivers

A device driver is a small computer program that lets the main operating system talk to physical hardware parts like printers, keyboards, or graphics cards.

1940s–1950s

Early Beginnings and Batch Systems

1960s

Multiprogramming and Time-Sharing

1970s–1980s

Personal Computers and GUIs

1990s–Present

Open Source, Mobile, and Cloud

System Calls

A formal request from a regular program to the operating system kernel to perform a privileged task like reading a file or accessing hardware.

Interrupts

is an emergency alert signal sent to a computer’s main processor (CPU) telling it to pause its current work, handle an urgent event, and then return to what it was doing

CPU Utilization

How much time the CPU is busy.

Throughput

How many jobs/processes are completed in a given amount of time.

Turnaround Time

How long it takes from submitting a process until it finishes.

Waiting Time

How long a process spends waiting in the ready queue.

Response Time

How long it takes before a system first responds to a request.

Latency

The delay between a request and the corresponding response.

Batch Operating System

An OS that groups similar user jobs into sequential batches to run without direct user interaction

Multi-Programming System

A system architecture where multiple distinct programs reside in the main memory simultaneously

Multi-Processing System

An OS configuration that coordinates the simultaneous execution of processes across two or more physical Central Processing Units (CPUs) within a single computer system.

Multi-Tasking Operating System

A logical extension of multiprogramming that allows a single user to run multiple applications concurrently

Time-Sharing Operating System

A specific multitasking deployment where a single server's CPU time is divided among multiple interactive users via a round-robin scheduling algorithm and strict time quantums.

Distributed Operating System

A system that manages a collection of independent, physically separated computational nodes connected via a network.

Network Operating System

An OS running on a dedicated server that provides the software protocols necessary to manage data, users, groups, security, and peripheral devices across a Local Area Network (LAN).

Real-Time Operating System

A specialized OS built for environments where processing must happen within strict, deterministic time constraints. A delay in output or task completion constitutes a total system failure.

CPU BURST

Period during which a process executes on the CPU

I/O BURST

Period when a process performs/waits for I/O

CORE

Independent execution unit within a processor

CONTEXT SWITCH

Switching CPU execution from one process/thread to another

CPU Scheduler

It is often called the short-term scheduler, selects a process/thread from the ready queue to execute.

Scheduling Policy

The general rule for deciding who should run.

Scheduling Algorithm

The specific procedure used to implement the decision.

Preemptive Scheduling

The OS can interrupt a running process and give the CPU to another process.

Non-preemptive scheduling

Once a process gets the CPU, it generally keeps it until it finishes

Context Switching

A context switch involves saving/restoring relevant execution state so CPU execution can move between processes or threads.

Context-Switch Overhead

The CPU spends time performing the switch rather than executing application instructions.

Completion Time (CT)

is the time at which the process finishes.