In web technology and networking, which of the following lists the three main types of web based environments used in organisations?

Introduction / Context:
When people talk about web environments in an organisational context, they often refer to the different network scopes under which web applications are deployed and accessed. Common terms include internet, intranet, and extranet. These concepts are important in interview questions because they highlight how access control, security, and audience differ for each environment, even when the underlying web technologies are similar.

Given Data / Assumptions:

• We are discussing high level web environments, not just software deployment stages.
• Organisations may expose some web applications to the public and others only internally.
• The question asks for the set of environment types that are standard in web and networking terminology.

Concept / Approach:
The internet is the global public network that connects millions of computers and users worldwide. An intranet is a private, internal web environment accessible only within an organisation, usually protected by a firewall. An extranet extends selected intranet resources to trusted external partners, vendors, or customers using secure access technologies such as VPNs or secure portals. These three together form the classic classification of web environments used when planning web applications and access policies.

Step-by-Step Solution:
Step 1: Define internet as the huge public network where publicly accessible websites and services live, such as public company websites and online shops. Step 2: Define intranet as a private web environment inside an organisation, accessible only to employees or authenticated internal users over the local network or VPN. Step 3: Define extranet as a controlled extension of the intranet that allows selected external partners, suppliers, or clients to access certain resources securely. Step 4: Recognise that these three types describe where and how web content is exposed rather than describing different stages of development. Step 5: Conclude that internet, intranet, and extranet are the standard web environment types referred to in many exam and interview questions.

Verification / Alternative check:
Most networking and web technology textbooks describe intranet as an organisation internal web, extranet as a limited access extension for outsiders, and internet as the public global network. Diagram examples often show a firewall separating the intranet from the internet and a secure gateway for extranet access. This confirms that these three names together represent the classic classification of web environments.

Why Other Options Are Wrong:
Option A is wrong because development, testing, and production refer to software lifecycle stages, not network based web environments. Option B is incorrect because mobile, desktop, and cloud describe device types or hosting models, not the scope of network access. Option D is wrong because client, server, and database describe architectural tiers, not distinct web environments exposed to different user groups.

Common Pitfalls:
A typical source of confusion is mixing up deployment environments like staging and production with network scopes like intranet and internet. Another pitfall is assuming that intranet must be completely disconnected from the internet; in practice it is usually separated logically and protected by firewalls, but users may still have internet access from intranet machines. Understanding the roles of internet, intranet, and extranet helps in designing secure web applications and deciding where they should be hosted.

Final Answer:
The three main types of web based environments are internet, intranet, and extranet, which define different scopes of web access in and around an organisation.