Perplexity.ai is an AI-powered search engine and conversational assistant launched in 2022. It is designed to provide accurate and informative answers to user queries by leveraging natural language processing and large language models.1 The key differences between Perplexity.ai and traditional search engines are:

1. Personalized search results: Perplexity.ai interprets the context of user queries to deliver personalized search results, rather than just returning a list of links.1

2. Inline citations: Perplexity.ai provides answers with inline citations to the sources used, allowing users to verify the information.13

3. Focus on recency: Perplexity.ai prioritizes newer sources to avoid outdated information, and allows users to ask follow-up questions that are interpreted in the same context.1

4. Freemium model: Perplexity.ai offers basic search functionalities for free, while its paid "Pro" version provides additional features like the ability to upload and analyze local files, generate images using AI, and access an API.12

5. Powerful language model: Perplexity.ai is built using OpenAI's GPT-3.5 model, combined with its own large language model that incorporates natural language processing capabilities. The paid "Pro" version also has access to more advanced models like GPT-4 and Claude 3.12

In summary, Perplexity.ai is a unique AI-powered search engine that aims to provide accurate, up-to-date, and well-cited information to users, while offering a range of advanced features through its paid subscription model.123