Which one of the following websites is a general-purpose web search engine that indexes and searches pages across the Internet?

Introduction / Context:
The modern web offers many different types of platforms, including search engines, social media networks, discussion forums, and content sharing sites. A web search engine is a specific type of service that crawls and indexes websites and then allows users to search this index using keywords. This question tests whether you can recognise which of the given websites is a general purpose search engine rather than a social or content platform.

Given Data / Assumptions:

• The options are Bing, Reddit, Pinterest, and Twitter.
• We assume their widely known roles on the Internet.
• Search engines provide web wide search results.
• Other sites focus on user generated content and social interaction.

Concept / Approach:
Bing is a web search engine developed by Microsoft. It crawls websites, builds a large index of pages, and returns search results for any topic. Reddit is primarily a discussion and community platform where users post links and comments organised into subreddits. Pinterest is a visual discovery and bookmarking platform that lets users save and share images and ideas. Twitter (now often called X) is a microblogging and social media service where users post short messages and follow others. Although these platforms may include their own internal search features, they are not general web search engines. Therefore, Bing is the correct answer.

Step-by-Step Solution:
Step 1: Examine Bing. Bing provides a search box where users can enter queries; it returns web pages from many different domains, functioning as a full web search engine. Step 2: Examine Reddit. Reddit organises user posts into forums; its search feature only searches within Reddit's own content, not across the entire web. Step 3: Examine Pinterest. Pinterest focuses on images and ideas pinned to boards; its search operates within its own platform rather than across the Internet. Step 4: Examine Twitter. Twitter allows users to post and search short messages (tweets) on its own servers, not as a web wide search engine. Step 5: Conclude that Bing is the general purpose web search engine in the list.

Verification / Alternative check:
If you enter a general knowledge query into Bing, you receive links to many different websites, news articles, and images from across the Internet. This behaviour is characteristic of a search engine. On Reddit, Pinterest, and Twitter, search results are limited to content stored on those specific platforms and do not index the full web. Official descriptions of Bing call it a web search engine, whereas documentation for Reddit, Pinterest, and Twitter describe them as community or social networking services. This confirms that Bing is the only true web search engine among the options.

Why Other Options Are Wrong:
Option B (Reddit): A social news aggregation and discussion site, not a general web search engine. Option C (Pinterest): A visual discovery and bookmarking platform focused on images and ideas, not on web wide search. Option D (Twitter): A microblogging and social networking site, not primarily designed as an Internet search engine.

Common Pitfalls:
Some learners think that any site with a search bar is a search engine. However, many social and content platforms include internal search to navigate their own posts, which is different from crawling and indexing external websites. Exam questions use search engine in the traditional sense of services like Bing, Google, and Yahoo that index the broader web. Keeping this distinction in mind helps you quickly identify Bing as the correct choice here.

Final Answer:
The website that is a general purpose web search engine is Bing.