Kiến thức Cơ bản về CNTT và Excel

1. Understanding the Byte and the Bit

In digital computing, the smallest unit of data is the bit, which can hold a value of 0 or 1. A group of eight bits forms a byte. This relationship is constant across all modern computer architectures.

• 1 byte = 8 bits
• Bits are the building blocks of all higher‑level data structures (characters, numbers, images, etc.).
• Memory sizes are usually expressed in multiples of bytes (KB, MB, GB, TB).

Memory‑mnemonic tip: "A byte is eight bright lights" – imagine eight LEDs turning on to represent a byte.

2. Networking Basics: The Role of a Router

Connecting computers to each other or to the Internet requires networking hardware. Among the most common devices is the router. Unlike RAM or CPU, a router does not store data for programs; instead, it directs data packets between networks, deciding the best path for each packet.

• Router – routes traffic, provides NAT, DHCP, and often Wi‑Fi.
• Other devices mentioned in the quiz (RAM, CPU, ROM) serve different purposes: RAM stores temporary data, CPU processes instructions, ROM holds permanent firmware.

Remember: Router = “control” of the network, like a traffic officer guiding cars.

3. Computer Hardware Terminology: CPU, RAM, and Storage

When you read a computer specification such as "CPU 1.8 GHz, RAM 20 GB, HDD 1 TB", each number describes a distinct component:

• CPU speed (GHz) – how many cycles the processor can perform per second.
• RAM size (GB) – the amount of volatile memory available for active programs.
• Storage capacity (GB/TB) – permanent space for files, operating system, and applications.

In the quiz, the 20 GB figure refers to RAM capacity. RAM is temporary; when the computer powers off, its contents disappear.

Mnemonic: RAM = "Random‑Access Memory", the short‑term memory of the computer.

4. Excel Essentials: Finding the Maximum Value

Excel provides a rich library of functions. To locate the highest number in a range, use the MAX function.

=MAX(A1:A10)

This formula scans cells A1 through A10 and returns the largest numeric entry. Other related functions include:

• MIN – returns the smallest value.
• AVERAGE – calculates the mean.
• SUM – adds all numbers together.

Tip: Remember that MAX stands for “Maximum”, the top of the list.

5. Excel Logic: Using the IF Function with AND

The IF function evaluates a condition and returns one value if the condition is true, another if it is false. Combining IF with logical operators such as AND allows you to test multiple criteria simultaneously.

=IF(AND(5>3, 2>=2), 2, 3)

Both conditions (5 > 3 and 2 ≥ 2) are true, so the formula returns 2. Other logical functions you may encounter:

• OR – true if any condition is true.
• NOT – reverses a logical value.

Remember: AND means “both must be true”.

6. PowerPoint Animation: Entrance Effects

PowerPoint offers three categories of animation: Entrance, Emphasis, and Exit. An Entrance effect makes an object appear on a slide. The most common term used in the UI is "Appear" (Vietnamese: "Xuất hiện").

• Entrance – object enters the slide (e.g., Fade, Fly In, Appear).
• Emphasis – highlights an already‑visible object (e.g., Pulse, Spin).
• Exit – removes the object from the slide (e.g., Disappear, Fade Out).

Quick recall: Entrance = "show up" = "Xuất hiện".

7. Reading Data Tables in Excel

Interpreting a spreadsheet often requires locating specific values. In the provided example, the product priced at 580 000 VND is Kaspersky. When scanning a table, follow these steps:

1. Identify the column that contains the price.
2. Use the FILTER or VLOOKUP function to isolate rows matching the target price.
3. Verify the product name associated with the matched row.

Similarly, counting rows in a list (e.g., a customer table) can be done manually or with the COUNTA function. The quiz indicated that the table contains 8 data rows.

Tip: Remember that header rows are not counted as data rows when using COUNTA on a specific column range.

8. Summary and Study Checklist

Below is a quick checklist to reinforce the key concepts covered in this course:

• Byte vs. Bit – 1 byte = 8 bits.
• Router – device that routes network traffic.
• RAM – temporary memory; size expressed in GB.
• MAX function – returns the highest value in a range.
• IF with AND – returns a result only when all conditions are true.
• PowerPoint Entrance – called "Appear" or "Xuất hiện".
• Table lookup – locate a product by price; count rows with COUNTA.

Review each point, practice with real Excel and PowerPoint files, and you will be well‑prepared for both academic quizzes and practical workplace tasks.