Internet
It is a global network of computers across the world wide web. It allows us to communicate, share information etc.
An example is the type of network we use to google words or visit nairaland.
There are some disadvantages such as virus, identity theft etc.



Intranet
It is a private network of computers within an organisation with its own firewall and server. It is a private network enterprise.
An example is a network server in an organisation (e.g microfinance bank). It nothing to do with outside of the organisation.
There are disadvantages such as loss of control, denial of service etc.

Extranet
It is a network within an organisation, using internet to connect to outsiders in controlled manner. It is a means of conveying information between members of the organisation and external members.
An example is a network used US CIA and connected externally by US FBI
A disadvantage is that it is vulnerable to security breaches.

Conclusion
Internet is open to entire world
Intranet is a private space
Extranet is a combination of both intranet and internet.







[url]
https://www.youtube.com/watch?v=HMicJFJhD44&t=327s [/url]

One mind is telling me to quit nairaland. Another mind is telling me not too. I'll soon find out which one is right.