The specific advantages of using Unicode over extended ASCII in web development are numerous and significant. Firstly, Unicode's comprehensive character set supports a vast array of languages and symbols, far exceeding the capabilities of extended ASCII. This inclusivity is essential in web development, as websites often need to cater to a global audience with diverse linguistic requirements. Secondly, Unicode ensures consistency across different browsers and devices. While extended ASCII might display correctly on one platform, it can lead to character encoding errors on another. Unicode, with its standardised encoding, ensures that text appears consistently, regardless of the user's device or browser, enhancing the user experience. Thirdly, Unicode supports the representation of a wide range of emojis and cultural symbols, which are increasingly important in digital communication. The ability to accurately and consistently represent these symbols is crucial for modern web design. Finally, Unicode's use in HTML and other web technologies has become a standard practice, aligning with best practices in web development and ensuring future compatibility and scalability.

The use of hexadecimal in colour coding significantly enhances web design and digital graphics by providing a precise and efficient way to specify colours. In web design, colours are often defined using hexadecimal values, where each colour is represented by a six-digit code. This code consists of three pairs of digits, each pair representing the intensity of the red, green, and blue components of the colour. For example, #FF5733 is a hexadecimal colour code, where FF represents a high intensity of red, 57 represents a moderate intensity of green, and 33 represents a low intensity of blue. This method allows for the specification of over 16 million different colours, offering designers a vast palette to work with. The precision of hexadecimal colour codes ensures consistency in colour representation across different browsers and devices. This consistency is crucial in maintaining the aesthetic integrity of a website or digital graphic. Additionally, hexadecimal codes are compact and easy to use, making them a preferred choice for designers who need to quickly and accurately define colours in their work.

Binary Coded Decimal (BCD) holds significant importance in financial systems, particularly concerning transaction accuracy. Financial computations often involve decimal arithmetic, and accuracy in these calculations is paramount. BCD represents each decimal digit separately, aligning directly with the decimal number system used in financial transactions. This alignment reduces the risk of rounding errors that can occur when converting between binary and decimal systems, as seen in pure binary representations. For example, when computing financial totals, interest rates, or currency conversions, BCD ensures that each decimal digit is accurately represented and processed. This precise representation is crucial in maintaining the integrity of financial data, avoiding discrepancies that could lead to significant errors in transactions, accounting, and reporting. Furthermore, BCD's structure facilitates easier implementation of decimal arithmetic operations in hardware, leading to more efficient and reliable financial computing systems. In summary, BCD's role in financial systems is pivotal in ensuring the accuracy and reliability of transactions and financial data processing.

Hexadecimal simplifies understanding and working with binary data in programming and debugging in several ways. Firstly, it offers a more compact and readable representation of binary data. A single hexadecimal digit represents four binary digits, reducing the length and complexity of binary strings. For instance, the binary number 110110101110 would be quite lengthy and prone to errors if written in full, but in hexadecimal, it's simply expressed as 1DAE. This compactness makes it easier for programmers to read, write, and debug code, especially when dealing with large values like memory addresses or colour codes. Secondly, hexadecimal aligns neatly with binary, as each hexadecimal digit corresponds directly to a four-bit binary sequence. This direct correlation facilitates quick and easy conversions between the two systems, which is particularly useful in low-level programming where direct manipulation of binary data is common. By simplifying these aspects, hexadecimal becomes an invaluable tool for programmers, aiding in clarity, reducing errors, and improving efficiency in coding and debugging processes.

Binary Coded Decimal (BCD) differs from pure binary in terms of storage efficiency primarily because BCD is less space-efficient. In BCD, each decimal digit is represented by its own four-bit binary sequence. For instance, the decimal number 255 would be represented in BCD as 0010 0101 0101, which takes 12 bits. In contrast, the same number in pure binary is 11111111, requiring only 8 bits. The implication of this decreased storage efficiency is significant in applications where memory space is a constraint. However, BCD is preferred in contexts where human readability and ease of conversion to and from decimal are more critical than saving space. BCD's structure simplifies operations like arithmetic calculations and digital display, making it ideal for devices like calculators and digital clocks. The trade-off between space efficiency and ease of use is a crucial consideration when choosing between BCD and pure binary for a particular application.