Lesson video

Hello, my name is Mrs. Holborow, and welcome to Computing.

I'm so pleased you could join me for the lesson today.

In today's lesson, we are going to be investigating protocols and the role protocols play in communication.

Welcome to today's lesson from the unit, "The Internet and Web Technologies." This lesson is called "Protocols." And by the end of today's lesson, you'll be able to explain how devices on a computer network use protocols to communicate.

Shall we make a start? We will be exploring these key words in today's lesson.

Let's take a look at them now.

Protocol.

Protocol, a set of rules used to allow devices to communicate with each other.

Secure protocol.

Secure protocol, a set of rules that protects data when devices communicate with each other.

Internet protocol.

Internet protocol, a set of rules that controls how data is sent over the internet, governing how data is addressed, for example.

Look out for these key words throughout today's lesson.

Today's lesson is broken down into two parts.

We'll start by describing how protocols secure communication, and then we'll move on to describe the role of protocols in communication.

Let's make a start by describing how protocols secure communication.

Laura says, "Hello, Jacob.

Did you know we follow lots of rules when we talk to each other?" Jacob says, "Yes.

It helps us understand each other properly.

Imagine trying to talk to someone who keeps talking over you." Laura says, "True.

I guess if we didn't follow those rules, it would be confusing." Jacob says, "Computers are the same when communicating over a network." Laura says, "So computers follow rules when they send data over the internet?" Jacob says, "Yes.

The rules tell computers how to send, receive, and understand messages." Laura has another question, "Can hackers use these rules to gain access to information sent over the internet?" That's a good question, Laura.

Jacob says, "There must be rules to stop hackers?" Computers need rules for communication.

These are known as protocols.

Protocols are the reason why billions of devices all over the world can communicate with each other.

Computers that need to communicate with each other will use the same protocols.

Protocols are needed for all sorts of reasons.

Here are some examples.

Planning routes, establishing communication, sending and receiving data, opening websites, and communicating securely.

Time to check your understanding.

Here's a true or false statement.

Protocols are only used for sending and receiving data, not for opening websites or communicating securely.

Is this statement true or false? Pause the video whilst you have a think.

Did you select false? Well done.

But why is it false? Protocols are used for a wide range of network activities, including planning routes, establishing communication, sending and receiving data, opening websites, and communicating securely.

A secure protocol is a type of communication rule that includes measures to protect data as it travels across a network.

Secure protocols ensure that the data cannot easily be read by unauthorised users.

The data has not been changed or tampered with during transmission.

The source of the data can be verified.

Secure protocols often use encryption, which converts the data into a secure format so that only the intended recipient can decode it.

Authentication confirms the identity of the sender or service.

Hypertext transfer Protocol Secure, or HTTPS, is used for secure web browsing.

HTTPS is considered the standard protocol for websites.

Data is encrypted when sent between your browser and a website using Transport Layer Security, TLS, like HTTP.

Time to check your understanding.

I have a question for you.

When you see HTTPS at the start of a website address, what does the S indicate about the connection? Is it A, the website is very simple.

B, the data sent between your browser and the website is encrypted.

Or C, the website is specifically for shopping.

Pause the video whilst you have a think about your answer.

Did you select B? Well done.

The S in HTTPS means that the data sent between your browser and the website is encrypted.

Transport Layer Security, TLS, is a protocol used to encrypt and protect data during transfer.

TLS is often used in services like HTTPS, email, and online messaging.

Data can't be read or changed while it's being transmitted.

Web browsers may show a padlock icon in the address bar to indicate a secure HTTPS connection.

However, Google Chrome removed the padlock icon in 2023 because HTTPS is now the default for most websites.

Google believed that the padlock gave a false sense of security as it only meant that the data was encrypted, not that the site was trustworthy.

TLS includes authentication as part of the connection process.

Authentication is the process of verifying that something or someone is genuine.

You may well have come across biometric authentication when you unlock your smartphone.

Websites use digital certificates to prove they are genuine.

These certificates are issued by trusted organisations called Certificate Authorities, or CAs.

When you visit a secure website using HTTPS, your browser checks the digital certificate and ensures the site is secure.

Okay, we're moving on to our first task of today's lesson, Task A.

For part one, I'd like you to explain what secure protocols are and describe three ways they protect data as it travels across a network.

For part two, I'd like you to give an example of a secure protocol used for browsing the worldwide web and explain how you can recognise it.

Pause the video whilst you complete the task.

How did you get on? Did you manage to answer the two questions? Great work.

Let's have a look at a sample answer together.

You were asked to explain what secure protocols are and describe three ways they protect data as it travels across a network.

Secure protocols are rules that include special measures to protect data as it travels across a network.

These protocols work by ensuring that the data cannot easily be read by unauthorised users, that the data has not been changed or tampered with during transmission, and that the source of the data can be verified as genuine.

For part two, you were asked to give an example of a secure protocol used for browsing the worldwide web, and explain how you can recognise it.

An example of a secure protocol used for browsing the worldwide web is Hypertext Transfer Protocol Secure, HTTPS.

You might recognise an HTTPS connection by looking for HTTPS at the beginning of the website address in the address bar.

Although removed in some browsers, a padlock icon traditionally appeared in the address bar indicate a secured connection.

So we've described how protocols secure communication.

Let's now move on to describe the role of protocols in communication.

Laura says, "So my smartphone can talk to my friend's tablet, even though they're made by different companies?" Yes, protocols are shared rules that allow billions of devices around the world to communicate no matter who makes them.

All devices follow the same protocols, which ensures they can send and receive data correctly.

Internet protocol, IP addresses, are structured like a postal address.

They have a logical structure and provide a set of instructions for reaching a destination.

Most IP addresses are assigned by routers.

The IP address can change when you move to a different location or connect to a different network.

An IP address is made up of four groups of numbers, each between 0 and 255, which are separated by a full stop.

Each address is unique for every device on the internet.

So this laptop has the IP address of 193.

163.

7.

53.

Time to check your understanding.

Which of these is a correctly formatted IP address? Is it A, 192.

168.

256.

10.

B, 10.

0.

0.

5.

2.

or C, 172.

16.

1.

1.

Pause the video whilst you have a think.

Did you select C? Well done.

A isn't a correctly formatted IP address because it contains the number 256, which is higher than the upper limit of 255.

B isn't a correct IP address because it contains five separate numbers.

So we've got 10, 0, 0, 5, and 2.

Remember, IP addresses are four individual numbers separated by a full stop.

Private IP addresses are used in private networks such as networks in schools, businesses, and homes.

Here's an example of a private IP address, 192.

168.

5.

43.

Public IP addresses can be viewed by other devices connected to the internet.

Here's an example of a public IP address, 77.

95.

35.

215.

There are two standards for IP addresses.

IPv4 gives 32-bit addresses, usually displayed as four sets of decimal numbers separated by dots, so just like the examples you've seen so far this lesson.

Here's another example, 192.

168.

1.

105.

These are widely used, but the number of available IPv4 addresses is limited, and they have already been used up globally.

So IPv6 has been introduced.

IPv6 uses 128-bit addresses, usually displayed as eight sets of hexadecimal numbers separated by colons.

So here's an example of an IPv6 address.

These have been designed to solve the shortage of IP addresses, allowing for a much larger number of unique addresses.

Transmission Control Protocol, or TCP, is a set of rules that breaks data into packets, sends them, and reassembles them at the destination.

User Datagram Protocol, UDP, is similar to TCP but doesn't guarantee delivery or order.

It is used in streaming and gaming where a missed packet isn't quite as crucial as in a financial file or document.

Hypertext Transfer Protocol, HTTP, can be used for retrieving information from remote servers across the worldwide web.

HTTP was the original way websites communicated over the internet.

Most websites have moved to HTTPS, which adds encryption.

File Transfer Protocol, FTP, is a method of transferring and sharing files across the internet.

The server opens a data connection over which the file will be sent, or sends an error code if there's been a problem with the request.

Time to check your understanding.

Which IP addressing standard is typically displayed using hexadecimal numbers separated by colons? Is it A, IPv4, B, IPv6, or C, public IP.

Pause the video Whilst you think carefully about your answer.

Did you select B? Well done.

IPv6 is typically displayed using hexadecimal numbers separated by colons.

Simple Mail Transfer Protocol, SMTP, is used to send an email to an email server.

The server returns a code indicating whether or not the email could be delivered.

Post Office Protocol, or POP, is used to request any new emails for a specific email account.

The server returns the emails and deletes them from the server.

Internet Message Access Protocol, IMAP, is another email protocol, but unlike POP, it synchronises with emails across multiple devices.

It is used to synchronise a client email account with an account on a mail server.

The server returns new emails, if there are any, and deletes any emails that were deleted locally on the client application.

This allows a user to use multiple devices to access their email account.

So for example, a user could access their email account using a laptop and a mobile phone, and both versions would be exactly the same.

Ethernet and wifi protocols manage lots of data transmissions on networks.

Okay, so we've looked at a lot of protocols in this section of the lesson.

Let's now move on to a task.

For part one, I'd like you to explain the overall role of protocols in communication, including why they are essential for billions of different devices around the world to successfully exchange information.

And then for part two, I'd like you to just take one of the protocols you've seen in this lesson and create a leaflet or poster to inform people about what it's used for and how it works.

Pause the video here whilst you complete the task.

How did you get on with the tasks? I'm sure you've done a fantastic job.

Let's look at a sample answer together.

For part one, the overall role of protocols in communication is to act as a set of rules that enable billions of different devices all over the world to communicate with each other successfully.

Protocols help in planning the routes data will take, establishing a connection between devices, managing the sending and receiving of data, and even ensuring that communication is secure.

Without protocols, communication between devices would be difficult because there would be no common way for devices to understand or to respond to each other.

For part two, you were asked to develop a poster.

So here's a quick example.

We've chosen HTTP.

We've got the title, "HTTP: The Web's Communication Rule!" and then we've added a bit of information about what is HTTP.

HTTP stands for Hypertext Transfer Protocol.

It's a fundamental set of rules that web browsers like Chrome or Safari use to exchange information with websites on the internet.

What is it used for? HTTP is used for retrieving information from websites across the worldwide web.

Every time a webpage loads, HTTP is operating in the background to make that happen.

Here's the second part of my poster.

How does HTTP work? Your web browser, Using HTTP, sends a request to a web server.

This request is for a specific webpage.

The web server then sends the information for that webpage, like text, pictures, and videos, back to your browser.

Your browser then uses that information to display the webpage on your screen.

Why is it important? Without HTTP, web browsers couldn't access most websites.

It's the primary rule that makes the worldwide web function.

I'm sure you've done a great job on your posters, so well done.

Okay, we've come to the end of today's lesson, Protocols, and you've done a fantastic job, so well done.

Let's summarise what we've learned in this lesson.

Protocols and secure protocols use sets of rules that enable billions of diverse devices globally to communicate successfully and securely.

Without agreed protocols, different devices would not be able to communicate or exchange information.

The internet protocol, IP, is a core set of rules.

IP addresses are a key part of this and are typically assigned to devices on a local network by the router.

I hope you've enjoyed today's lesson, and I hope you'll join me again soon.

Bye.