ChatGPT, developed by OpenAI, is the most widely recognized AI chatbot, though a range of alternative AI tools such as Google Gemini, Anthropic's Claude, and Perplexity are also available. Despite this, most users remain familiar only with ChatGPT. OpenAI has recently expanded ChatGPT's features, rolling out a memory function to free users as of June 2025. This update allows the chatbot to reference recent conversations for more personalized responses, a capability previously limited to paid subscribers. Users can opt out of the memory feature or use temporary chat modes for privacy. Effective use of ChatGPT relies on prompt engineering. Research shows that refining prompts—by specifying goal, context, format, and tone—can improve response quality. A 2024 study found that over 65% of users achieved better output after editing prompts, with prompt tweaks saving an average of 12 minutes per task. ChatGPT is used for a variety of tasks, including writing, editing, translation, summarization, coding, image creation, and as a conversational partner. Its technology is based on large language models trained on extensive datasets, but its knowledge is limited to its training data and does not reflect real-time events. Other AI tools such as Gemini, Perplexity, Notion AI, and Ideogram are increasingly integrated into user workflows, offering specialized functions like research, document analysis, productivity planning, and image generation. These alternatives, along with prompt engineering techniques, are supporting broader and more effective use of AI tools.