How does the computer know whether a binary pattern results in the display of a letter or number?

You (or the compiler you use) have to explicitly tell the computer how to interpret a bit string. So when you write code you'd have to specify "This is a character" or "This is a binary number", high level programming language have functions to make that easier.

How does a computer know how to display this information?

The computer know to display the info because it reads digital info in bits, and then outputs and converts those bits into visible things, like letters.

I didn't understand how 4 bits can represent 16 values.Could you please explain.Thanks

If we have 4 bits and each can be one of two values, then the number of combinations one can make with 4 bits is equal to 2*2*2*2 = 2^4 = 16.

"At 11:47, what are electromechanical transistors?"

it focuses on the interaction of electrical and mechanical systems as a whole and how the two systems interact with eachother.

How would a computer know if 1000011 in a text file represents the number 67 or the letter C?

It nows has a system in it and it travels as a bit it is converted into it when a computer reads it in 1's and 0's and is converted back into the digital form hope it helps🙂

Bits are binary digits (0 and 1)

I dont seem to understand a sequence of bits can anyone explain

When you have more than one bit (or wire), the number of possible values increases. In 1 bit there are two possible values: 1 or 0. In 2 bits, there are four possible values, or combinations: 00, 01, 10, 11. With each additional bit, the number of possible values/combinations goes up by a factor of two.

Main content

AP®︎/College Computer Science Principles

Course: AP®︎/College Computer Science Principles > Unit 1

Lesson 1: Bits and bytes

Bits (binary digits)

Google Classroom

Computers store information using bits. A bit (short for "binary digit") stores either the value

0

1

What fits in a bit?

A single bit can only represent two different values. That's not very much, but that's still enough to represent any two-valued state.

Is a lightbulb on or off?

State	Bit
A lightbulb that's off	$0$ ‍
A lightbulb that's on	$1$ ‍

Is a button enabled or disabled?

State	Bit
An enabled button that says "Submit"	$0$ ‍
A disabled button that says "Submit"	$1$ ‍

Is the current time AM or PM?

State	Bit
An alarm clock that says "9:35 AM"	$0$ ‍
An alarm clock that says "9:35 PM"	$1$ ‍

Check your understanding

Consider this settings screen for a Khan Academy user:

Which of the settings can be stored in a single bit?

Sequences of bits

Computers use multiple bits to represent data that is more complex than a simple on/off value.

A sequence of two bits can represent four (

2^{2}

) distinct values:

00

01

10

11

A sequence of three bits can represent eight (

2^{3}

) different values:

000

001

010

011

100

101

110

111

A sequence can represent many things: a number, a character, a pixel. Plus, the same sequence can represent different types of data in different contexts. The sequence

1000011

could represent

67

in a calculator application while also representing the letter "C" in a text file. Learn more in our lessons on Binary numbers and Storing text in binary

Check your understanding

How many different values can four bits represent?

Physical storage

Computers typically store bits using electromechanical transistors which can map electrical signals to either an on or off state. Learn more in our article From electricity to bits or this video on how transistors work.

🙋🏽🙋🏻‍♀️🙋🏿‍♂️Do you have any questions about this topic? We'd love to answer— just ask in the questions area below!

[Where is it?]

Want to join the conversation?

Sort by:

Jess S
Posted 3 years ago. Direct link to Jess S's post “How does the computer kno...”
How does the computer know whether a binary pattern results in the display of a letter or number?
Button navigates to signup pageComment on Jess S's post “How does the computer kno...”
(29 votes)
Answer
- Martin
  Posted 3 years ago. Direct link to Martin's post “You (or the compiler you ...”
  You (or the compiler you use) have to explicitly tell the computer how to interpret a bit string.
  
  So when you write code you'd have to specify "This is a character" or "This is a binary number", high level programming language have functions to make that easier.
  Comment on Martin's post “You (or the compiler you ...”
  (44 votes)
2_Vaz_Jesse
Posted 4 months ago. Direct link to 2_Vaz_Jesse's post “Why did they come to lear...”
Why did they come to learn 1s and 0s? Couldn't they learn our language?
Button navigates to signup pageComment on 2_Vaz_Jesse's post “Why did they come to lear...”
(4 votes)
Answer
- Giovanny Aimar Sanchez
  Posted 3 months ago. Direct link to Giovanny Aimar Sanchez's post “It's a computer lil bro”
  It's a computer lil bro
  Comment on Giovanny Aimar Sanchez's post “It's a computer lil bro”
  (27 votes)
Shwetha
Posted 3 years ago. Direct link to Shwetha's post “I didn't understand how 4...”
I didn't understand how 4 bits can represent 16 values.Could you please explain.Thanks
Button navigates to signup pageComment on Shwetha's post “I didn't understand how 4...”
(8 votes)
Answer
- KLaudano
  Posted 3 years ago. Direct link to KLaudano's post “If we have 4 bits and eac...”
  If we have 4 bits and each can be one of two values, then the number of combinations one can make with 4 bits is equal to 2*2*2*2 = 2^4 = 16.
  Comment on KLaudano's post “If we have 4 bits and eac...”
  (15 votes)
Brayden Weimholt
Posted a year ago. Direct link to Brayden Weimholt's post “How does a computer know ...”
How does a computer know how to display this information?
Button navigates to signup pageButton navigates to signup page
(9 votes)
Answer
- liangsamuel3
  Posted 4 months ago. Direct link to liangsamuel3's post “The computer know to disp...”
  The computer know to display the info because it reads digital info in bits, and then outputs and converts those bits into visible things, like letters.
  Button navigates to signup page
  (4 votes)
Judepius Ugwuanyi
Posted 3 years ago. Direct link to Judepius Ugwuanyi's post “"At 11:47, what are elect...”
"At
11:47
, what are electromechanical transistors?"
Button navigates to signup pageButton navigates to signup page
(7 votes)
Answer
- valeriaacesarr
  Posted a year ago. Direct link to valeriaacesarr's post “it focuses on the interac...”
  it focuses on the interaction of electrical and mechanical systems as a whole and how the two systems interact with eachother.
  Button navigates to signup page
  (3 votes)
Amily
Posted 4 months ago. Direct link to Amily's post “How would a computer know...”
How would a computer know if 1000011 in a text file represents the number 67 or the letter C?
Button navigates to signup pageComment on Amily's post “How would a computer know...”
(6 votes)
Answer
- anonymous
  Posted 4 months ago. Direct link to anonymous's post “It nows has a system in i...”
  It nows has a system in it and it travels as a bit it is converted into it when a computer reads it in 1's and 0's and is converted back into the digital form
  hope it helps🙂
  Button navigates to signup page
  (8 votes)
54918
Posted 9 months ago. Direct link to 54918's post “why is this topic so comp...”
why is this topic so complicated and stressful given the fact that i literally just found out about it today?
Button navigates to signup pageComment on 54918's post “why is this topic so comp...”
(8 votes)
Answer
- BenjaminW
  Posted 6 months ago. Direct link to BenjaminW's post “becus copeters are coplca...”
  becus copeters are coplcated.
  Button navigates to signup page
  (4 votes)
virriobelony80
Posted 5 months ago. Direct link to virriobelony80's post “I dont seem to understand...”
I dont seem to understand a sequence of bits can anyone explain
Button navigates to signup pageComment on virriobelony80's post “I dont seem to understand...”
(5 votes)
Answer
- chromedome
  Posted 5 months ago. Direct link to chromedome's post “When you have more than o...”
  When you have more than one bit (or wire), the number of possible values increases. In 1 bit there are two possible values: 1 or 0. In 2 bits, there are four possible values, or combinations: 00, 01, 10, 11. With each additional bit, the number of possible values/combinations goes up by a factor of two.
  Button navigates to signup page
  (6 votes)
kpendley
Posted a year ago. Direct link to kpendley's post “what are bits”
what are bits
Button navigates to signup pageButton navigates to signup page
(6 votes)
Answer
- tomiwa.
  Posted 7 months ago. Direct link to tomiwa.'s post “Bits are binary digits (0...”
  Bits are binary digits (0 and 1)
  Button navigates to signup page
  (4 votes)
Maide Ahsen Yücel
Posted 3 months ago. Direct link to Maide Ahsen Yücel's post “should i click for the 'l...”
should i click for the 'learn more about this lessons' ? are they include for the AP exam?
Button navigates to signup pageButton navigates to signup page
(7 votes)
Answer