What is ASCII and how is it different from Unicode?

In one line

The rule

ASCII is a character encoding standard that uses 7 or 8 bits to represent English letters, numbers, and some symbols. Unicode is a newer standard that uses more bits to represent characters from almost all languages and many symbols.

No formula is needed, but you can remember:

• ASCII: 7 bits (128 characters), sometimes 8 bits (256 characters)
• Unicode: 8, 16, or 32 bits (over 1,00,000 characters)

Let's understand it simply

Imagine you are making a list of all the letters and symbols you use in English. You give each one a number. This is what ASCII does. For example, 'A' is 65, 'B' is 66, and so on. But what if you want to write in Hindi, Tamil, or Chinese? ASCII does not have numbers for those letters.

Unicode is like a giant list. It gives a number to every letter, symbol, and emoji from almost every language in the world. So, you can write in Hindi, Tamil, Chinese, or even use emojis—all because of Unicode.

How it works

1. ASCII:

• Only English letters, numbers, and a few symbols.
• Each character gets a number from 0 to 127 (7 bits).
• Example: 'A' is 65, 'a' is 97.

1. Unicode:

• Covers almost all languages and symbols.
• Each character gets a unique number (code point).
• Can use 8, 16, or 32 bits, so it can handle over 1,00,000 characters.
• Example: 'A' is still 65, but 'अ' (Hindi) is 2309, '你' (Chinese) is 20320.

The story behind it

ASCII was created in the 1960s in the USA to help computers talk to each other using English. It was enough when computers were mostly used in America. But as computers spread worldwide, people needed to write in their own languages. Unicode was created in the 1990s by a group called the Unicode Consortium. Their goal was to make one system for all languages, so everyone could use computers in their own script.

Where you see it in real life

• Sending a text in English: Each letter uses ASCII or Unicode.
• Typing in Hindi or Tamil on WhatsApp: Unicode makes it possible.
• Emojis in messages: Unicode gives each emoji a code.
• Programming: When you save a file, the computer uses Unicode to store all characters.
• Websites: Unicode lets you see many languages on one page.
• ATM screens: Multiple languages are shown using Unicode.

Why it matters

• Unicode allows you to use computers in any language, not just English.
• It helps people from different countries share information easily.
• It makes sure your name or message looks the same on every device.
• Unicode supports new symbols, like emojis, which are used daily.

Common mistakes

• Thinking ASCII can show all languages—ASCII is only for English and some symbols.
• Believing Unicode is just a bigger ASCII—Unicode is much more; it supports scripts from all over the world.
• Mixing up bits and characters—ASCII uses 7 or 8 bits, Unicode can use 8, 16, or 32 bits.

Remember it

ASCII is for English; Unicode is for every language and emoji.