Which of the following statements about the relationship between an intranet and the global Internet is correct?

Introduction / Context:
An intranet is a private network that is usually used within an organisation, while the Internet is the global public network that connects millions of computers worldwide. Even though their scope and access rules are very different, they are built on similar networking technologies. This question tests whether you know which statement about how intranets and the Internet relate at the protocol level is correct.

Given Data / Assumptions:

• An intranet is a private network used inside an organisation.
• The Internet is the global public network that spans the world.
• Both intranet and Internet must use some set of networking protocols to move data.
• The options mention encryption, protocol similarity, speed, and use of the same protocol.

Concept / Approach:
Both intranets and the Internet are typically built on the TCP or IP protocol suite. The same basic protocols such as IP, TCP, UDP, HTTP, and others are used to send and receive data packets. An intranet is usually restricted by access controls or firewalls, but the underlying communication protocols are the same as those of the public Internet. Encryption is optional in both cases rather than always required, and speed depends on network design, not on whether it is an intranet or the global Internet. Therefore, the correct statement is that they use the same protocol.

Step-by-Step Solution:
Step 1: Recall what protocol suite underlies most modern networks. Most commercial networks, whether private or public, use the TCP or IP protocol suite. Step 2: Apply this to intranets. An intranet is usually just an organisation's private IP network protected by routers and firewalls. Step 3: Apply this to the Internet. The Internet is a huge collection of IP networks joined together, also using TCP or IP. Step 4: Compare the options. Encryption is possible on both but not always required, speed is not always slow, and the best description is that they use the same protocol. Step 5: Conclude that “They use the same protocol” is the correct statement.

Verification / Alternative check:
Networking textbooks consistently describe an intranet as an internal TCP or IP based network that uses Internet technologies inside an organisation. They explain that web servers, mail servers, and other services on an intranet are accessed using the same protocols as on the public Internet. The main difference is that an intranet restricts access to authorised users. Speed can actually be higher on an intranet because the network is smaller and less congested, and encryption is an optional security feature on both intranet and Internet connections. These points confirm that protocol usage is the key similarity and that they use the same protocol stack.

Why Other Options Are Wrong:
Option A (Encryption is necessary): Encryption is recommended but not mandatory for either intranets or the public Internet. Many internal services run without encryption. Option B (They use similar protocol): This is vague and suggests only similarity. In fact, intranets normally use exactly the same TCP or IP protocols as the Internet. Option C (Speed is slow): Speed can vary; intranets are often faster than Internet connections, so this is not a generally true statement.

Common Pitfalls:
Students sometimes confuse security and performance with protocols. They may think an intranet must be encrypted or that the Internet is always slower because it is larger. Others pick “similar protocol” because it sounds safe, but exam style questions usually highlight that intranets are built using the same Internet technologies and protocols. To avoid errors, remember that protocol refers to the rule set for communication, and both intranet and Internet use the same TCP or IP based set of rules.

Final Answer:
The true statement is that intranets and the Internet use the same protocol stack such as TCP or IP.