Good day, everyone! Today, we’re going to delve into the realm of computer hardware, exploring the devices that make our computing experiences possible. Let’s embark on this journey to understand the essential components that power our digital world.

I. Input Devices

1. Keyboard

• A computer keyboard is an input device that allows users to input data and commands into a computer or other devices.

（1）Layout

• Keyboards typically follow the QWERTY layout, named after the first six letters in the top row of keys.
• Other layouts, such as AZERTY or DVORAK, are used in different regions or for specific purposes.

（2）Key Types

• Alphanumeric Keys: Include letters and numbers.
• Function Keys: Located at the top and used to perform specific functions in different applications.
• Control Keys: Include Shift, Ctrl (Control), and Alt (Alternate), used in combination with other keys for various commands.
• Navigation Keys: Include arrows and keys like Home, End, Page Up, and Page Down.
• Special Keys: Include Enter (Return), Backspace, Delete, and the Spacebar.

（3）Functionality

• Typing: The primary function is to input text and characters.
• Shortcuts: Many keyboards have shortcut keys to quickly perform common tasks.
• Commands: Used to control the computer, execute commands, and interact with software.

（4）Connectivity

• Wired Keyboards: Connect to the computer using a USB or PS/2 port.
• Wireless Keyboards: Connect via Bluetooth or other wireless technologies.

（5）Ergonomics

• Some keyboards are designed with ergonomic features to reduce strain and discomfort during extended use.

（6）Multimedia Keys

• Modern keyboards often include multimedia keys for controlling audio and video playback.

（7）Gaming Keyboards

• Designed for gaming enthusiasts, these keyboards may have additional features like customizable keys and backlighting.

（8）Mechanical vs. Membrane Keyboards

• Mechanical Keyboards: Have individual mechanical switches for each key, providing a tactile feel and audible feedback.
• Membrane Keyboards: Use pressure pads beneath the keys, offering a softer feel.

（9）Backlit Keyboards

• Some keyboards have backlighting, allowing users to see the keys in low-light conditions.

（10）Customization

• Many keyboards offer customization options, allowing users to assign specific functions to keys.
• Understanding the features and functionality of a keyboard is essential for efficient and comfortable computer use.

2. Mouse

Composition:
Left Button: Primary click.
Mouse Wheel: Scroll functionality.
Right Button: Secondary click.
Operations:
Point to: Directing the cursor.
Click: Single-click to select objects.
Double-Click: Opens documents or starts software.
Right-Click: Opens a shortcut menu.
Drag: Moves or resizes selected objects.

3. Scanner, Microphone, and Web-Cam

These devices capture visual, audio, and video inputs for various applications.

II. Storage Devices

1. Cache

High-speed memory used to store frequently accessed data.

2. Primary Storage Device

RAM (Random Access Memory):
SRAM (Static RAM): Faster but more expensive.
DRAM (Dynamic RAM): Slower but more cost-effective.
Storage Units:
GB (Gigabytes): Measurement of storage capacity.

3. Secondary Storage Device

Floppy Disk, Hard Disk, Solid State Disk (SSD), Mobile Hard Disk, U Disk, CD-ROM, DVD, BDVD:
Various storage devices with different capacities and functionalities.

III. Control Unit

• The control unit manages and coordinates the computer’s operations.

IV. ALU

• The ALU performs arithmetic and logical operations.

V. Output Devices

1. Display (Monitor)

Visual output for user interaction.

2. Printer

Types:
Needle Printer, Inkjet Printer, Laser Printer.

3. Speaker and Plotter

Speaker: Produces audio output.
Plotter: A device for producing high-quality graphics.

In conclusion, understanding computer hardware is crucial for anyone venturing into the digital landscape. Today’s overview is just the beginning of our exploration. As we delve deeper into each component in future sessions, you’ll gain a comprehensive understanding of the hardware that powers the technology we use daily.

Thank you for joining today’s session, and I look forward to our continued exploration of the fascinating world of computers.