What is a Function of the BIOS? Explained for IT Certification Exams

For anyone pursuing an IT certification or preparing for technical exams, understanding what is a function of the BIOS? is essential. The Basic Input/Output System (BIOS) plays a critical role in computer startup and hardware interaction, making it a key topic in both academic and certification-based learning.

At DumpsQueen, our mission is to help learners master core computer concepts with ease and clarity. This blog covers everything you need to know about the BIOS—what it is, what it does, and how it’s tested in exams. Whether you're preparing for CompTIA A+, Cisco, or Microsoft certifications, you’ll find valuable insights here.

What is the BIOS?

BIOS stands for Basic Input/Output System. It is firmware, meaning it's software embedded into a hardware chip on the motherboard of a computer. Its primary job is to start the system and prepare it to load the operating system from storage into memory. In other words, the BIOS gets everything ready so your operating system can take over.

The BIOS is the first code that runs when a computer is powered on. It ensures all hardware components are functioning correctly before handing control over to the operating system.

What is a Function of the BIOS?

If you’ve ever asked yourself “what is a function of the BIOS?”, here’s the direct answer: the BIOS performs essential tasks like initializing hardware components, performing POST (Power-On Self Test), and launching the bootloader that loads your operating system.

Let’s break this down into the main functions:

1. POST (Power-On Self Test)

One of the most vital functions of the BIOS is the Power-On Self Test. When you power on your computer, the BIOS checks all essential hardware components—like RAM, CPU, hard drives, and graphics card—to ensure they are functioning correctly. If a component fails, the BIOS will either display an error or issue beep codes depending on the motherboard.

2. Bootstrapping or Boot Loader Execution

After the POST, the BIOS searches for a bootable device (usually a hard drive, SSD, or USB). Once found, it hands over control to the bootloader on that device, which in turn loads the operating system. Without this step, the OS wouldn’t be able to start.

3. CMOS Setup Utility Access

Another function of the BIOS is providing access to the CMOS setup utility, also known as the BIOS setup utility. This is where users can configure system-level settings like date/time, boot order, hardware configurations, CPU clock speeds, and fan speeds.

4. Hardware Initialization

The BIOS initializes and tests system hardware components. It enables communication between devices by loading drivers stored on the firmware, such as keyboard controllers, display adapters, and storage controllers. These drivers allow the operating system to interact with the hardware later on.

5. Power Management

BIOS also provides basic power management features, allowing it to manage states like sleep, hibernation, and wake-on-LAN. These settings can be fine-tuned through the BIOS setup utility.

6. Security Functions

Modern BIOS chips offer security features like BIOS password protection and Trusted Platform Module (TPM) integration. This can help prevent unauthorized access to system settings or even data encryption.

Why is BIOS Important for Exams?

If you're studying for any computer fundamentals or hardware-focused exam, there's a strong chance you'll encounter the question: what is a function of the BIOS?

Understanding BIOS functionality helps answer exam questions related to system startup, troubleshooting, configuration, and security. It’s often tested in exams like:

CompTIA A+ Core 1 (220-1101)
Microsoft Modern Desktop Administrator (MD-100)
Cisco IT Essentials
HP and Dell hardware certifications

BIOS vs UEFI: What’s the Difference?

BIOS has been largely replaced in modern systems by UEFI (Unified Extensible Firmware Interface), which offers a graphical interface, faster boot times, and better security. However, the core concept remains the same: initialize hardware and start the operating system.

Still, many certification exams refer to BIOS since it's foundational knowledge.

Key BIOS Terms to Know

To fully grasp what is a function of the BIOS?, it helps to understand these related terms:

Firmware: Software stored in hardware (e.g., BIOS chip)
POST: Initial test run to verify hardware functionality
CMOS: Stores BIOS settings like date/time and hardware configuration
Bootloader: A program that loads the OS from storage
Secure Boot: A feature that helps protect the system from malware during startup

How to Access the BIOS?

To enter the BIOS setup utility, restart your computer and press a specific key during boot—commonly Del, F2, or F10 depending on the manufacturer. From there, you can adjust boot priority, set passwords, or configure hardware settings.

Can the BIOS Be Updated?

Yes, BIOS firmware can be updated, a process known as "flashing the BIOS." This is typically done to add support for new hardware or fix bugs. However, it should be approached with caution. An incorrect BIOS update can render a system unusable.

Real-Life Example: BIOS in Troubleshooting

Let’s say your system won't boot and only shows a black screen. The BIOS beep codes (e.g., one long, two short) can indicate what went wrong—like a graphics card failure. Understanding the BIOS function allows technicians to identify and resolve such problems efficiently.

Summary: What is a Function of the BIOS?

Let’s recap the major functions of the BIOS:

Initiates the POST to check hardware components
Loads the bootloader to start the OS
Allows access to the CMOS setup utility for system configuration
Initializes essential hardware so the OS can use them
Provides power management and security features

Whether you’re troubleshooting a system, configuring settings, or preparing for a certification exam, understanding what is a function of the BIOS? is a must-have skill.