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Basics of computer science

Hello Readers,

This blog is all about some basic concepts in the computer science world which all must be known about it. you all are using computers, right? do you know how the computer stores our human-readable information within it?

Let’s start with bit and bytes first.

You may hear these terms in internet speed or storing device like HDD, memory card, pen drives etc.. example: Our internet speed is 1Mbps or 5 Mbps or I have 1TB of HDD.

What is Bit?

The bit is the smallest unit of data used to store information on the computer. A bit has a single binary value, either 0 or 1.

|0|

Why 0 and 1?

The computer is an electronic digital device made up by combining different hardware together. So hardware understands the only electronic language that means low or high voltage/current. So to express it we use 0’s and 1’s. 0 means low voltage and 1 means high voltage.

What is Bytes?

The means collection of 8 bits.8 bits form a single byte.

|1|0|0|1|0|0|0|1|

What is the difference between Mbps and MBps?

Mbps means megabits per second. Mb is used in reference to download and upload speeds.

MBps stands for megabytes per second. MB is used in reference to file size, or the amount of data transferred.

So, the difference is between bits and bytes. Yes.

1 Byte = 8 bits

This means,

1MBps = 8Mbps

That is eight times the difference. This is true for all units mentioning bits and bytes like kbps, Gbps, Tbps etc.

1KBps = 8kbps

1GBps = 8Gbps

1TBps = 8Tbps

Now let’s discuss how the computer stores our textual language into the machine.

What is a character?

A character is any letter, number, space, punctuation mark, or symbol that can be typed on a computer. It takes 1 byte to store a single character. It varies according to the different operating system.

Why 1 byte?

There is 128 character present so to store 128 characters we need 7 bits to store it. 2^7 = 128.

So here we need to store the characters on the hardware but the machine does not understand the character. So for this we need to encode the characters into machine understandable code.

What is Encoding?

Encoding is the process of converting data from one form to another. There are several types of encoding, including image encoding, audio, video encoding, and character encoding.

What’s a character encoding?

Words and sentences in the text are created from characters. Examples of characters include the Latin letter á or the Chinese ideograph 請 or the Devanagari character ह.

Characters that are needed for a specific purpose are grouped into a character set. To refer to characters in an unambiguous way, each character is associated with a number, called a code point.

Basically, you can visualize this by assuming that all characters are stored in computers using a special code, like the ciphers used in espionage. A character encoding provides a key to unlock (ie. crack) the code.

It is a set of mappings between the bytes in the computer and the characters in the character set. Without the key, the data looks like garbage.

So, when you input text using a keyboard or in some other way, the character encoding maps characters you choose to specific bytes in computer memory, and then to display the text it reads the bytes back into characters.

So that the text is saved using one of the different types of character encoding.

Types of encoding :

• ASCII : An encoding for English characters based on 7-bits that are mapped to 128 characters. ASCII is an American standard that dates back to the early 1960s. It has been changed numerous times throughout its history including an expansion to competing versions of 8-bit ASCII. It is extremely limited, even for English, and led to a number of character sets being developed for every language.

• Unicode :

Unicode is an international standard first released in the early 1990s to unify 135 modern and historic languages under a common character set. It currently has 128,237 characters that are increased over time. Its current maximum is 1,114,112 characters that represent the hexadecimal numbers 0 to 10FFFF. Unicode is a standard for a character set and not a character set itself.

• UTF-8 :

UTF-8 is a character set that implements Unicode. Despite its name, UTF-8 isn’t a static 8-bit encoding but instead is a variable length encoding that uses up to 32 bits. It encodes the most common characters, such as basic numbers and English with 8-bits. This makes it efficient for most data. Another advantage of UTF-8 is that for English, it is identical to ASCII.

• UTF-16

• UTF-32