What is BIOS?
BIOS stands for Basic Input/Output System.
✅ Simple Definition for Exams:
BIOS is a software stored in ROM that starts when the computer is powered on and helps load the operating system.
🧠 Detailed Explanation:
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BIOS is a firmware (software embedded in hardware) stored on the motherboard ROM.
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It performs the POST (Power-On Self Test) to check if hardware like RAM, keyboard, and disk drives are working.
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Then it locates and loads the operating system from hard drive or SSD.
🔧 Main Functions of BIOS:
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POST (Power-On Self Test): Checks system hardware.
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Boot Loader: Loads operating system into RAM.
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CMOS Setup Utility: Allows user to change system settings like time, boot order.
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Hardware Control: Helps CPU communicate with keyboard, hard drive, etc.
🧪 Example:
When you switch on your computer, the BIOS starts before Windows or any OS. It checks your hardware and then starts loading your operating system from the hard disk.
📝 Important Points for Exams:
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BIOS is stored in ROM.
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BIOS is the first software that runs when you start a PC.
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BIOS helps in booting the computer.
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BIOS setup can be accessed by pressing keys like F2, F10, Del during startup.