What Is ChatGPT? Everything You Need to Know

ChatGPT has quickly grown from a research project to one of the most recognized names in artificial intelligence. In this article, we will look at the history of ChatGPT, highlighting important milestones up to April 2025. We’ll also explain what OpenAI – the company behind ChatGPT – is and its mission, along with major projects such as GPT, Codex, and DALL-E. We’ll also discuss ChatGPT’s main features, such as generating text, writing code, analyzing images, and integrating with other tools. The goal is to provide a clear and easy to understand overview for a general audience.

History of ChatGPT

ChatGPT’s development has closely followed the progress of OpenAI’s language models (the GPT series). Below is a high-level timeline of its evolution from early research to today:

• December 2015 – OpenAI Founded: Tech leaders like Sam Altman, Elon Musk, and Ilya Sutskever founded OpenAI as an AI research lab with the mission to ensure artificial general intelligence (AGI) benefits all of humanity. This laid the foundation for the GPT research that would later power ChatGPT.
• June 2016 – Early Generative Model Research: OpenAI published its first research on generative models, teaching AI to create data (like images or text) similar to its training examples.
• February 2019 – GPT-2 and Human Feedback: OpenAI released GPT-2, a language model with 1.5 billion parameters. They also began experimenting with human feedback to improve the model’s responses, a technique that would later shape ChatGPT.
• June 2020 – GPT-3 Released: OpenAI introduced GPT-3, a powerful model with 175 billion parameters. It could generate fluent text for a wide range of tasks, from answering questions to writing essays, paving the way for conversational applications like ChatGPT.
• January 2022 – InstructGPT: OpenAI’s research on InstructGPT showed that fine-tuning models with human instructions improved their ability to follow prompts while reducing harmful outputs. This was a key step toward ChatGPT’s helpful and safe behavior.
• November 30, 2022 – ChatGPT Launch: OpenAI released ChatGPT as a free research preview, based on a refined version of GPT-3.5. It quickly gained popularity, reaching over 1 million users within a week and 100 million by January 2023.
• February 1, 2023 – ChatGPT Plus: OpenAI introduced ChatGPT Plus, a $20/month subscription offering faster speeds, priority access during peak times, and early access to new features, while keeping the free version available.
• February 2023 – Microsoft Integration: Microsoft began integrating ChatGPT’s technology into its products, including new Bing features powered by ChatGPT’s AI, marking the beginning of widespread use in software.
• March 1, 2023 – Developer API: OpenAI launched the ChatGPT API, allowing developers to integrate its capabilities into their apps. This opened new opportunities for businesses to use ChatGPT’s AI for custom chatbots and assistants.
• March 14, 2023 – GPT-4 and Competitors: OpenAI introduced GPT-4, which featured better performance and the ability to process image inputs (multimodal). The same day, Anthropic and Google launched their own AI models, increasing competition in the field.
• Late March 2023 – Plugin Ecosystem: OpenAI added plugins to ChatGPT, enabling it to access external tools and real-time information, such as web browsing, code interpretation, and third-party services.
• March 31, 2023 – Temporary Ban in Italy: Italy temporarily banned ChatGPT over privacy concerns. OpenAI responded by improving data controls and age verification, lifting the ban by April 2023.
• May 2023 – Official Mobile App: OpenAI launched the ChatGPT iOS app, followed by an Android version in July 2023, making it easier for users to access ChatGPT on their phones with voice input and synced conversations.
• Mid-2023 – Continued Growth: By mid-2023, ChatGPT’s user base grew rapidly. OpenAI introduced features like Custom Instructions and launched ChatGPT Enterprise, which gained use in 80% of Fortune 500 companies.
• September 2023 – Multimodal ChatGPT (Vision & Voice): ChatGPT became multimodal, enabling Plus users to upload images for analysis and engage in voice conversations with the AI. This marked a significant expansion of its capabilities.
• November 2023 – OpenAI DevDay and GPT-4 Turbo: OpenAI unveiled GPT-4 Turbo and introduced custom GPTs, allowing users to create personalized AI assistants. In January 2024, OpenAI launched the GPT Store for sharing and downloading custom models.
• Early 2024 – Evolving the Platform: OpenAI refined its platform, replacing the plugins beta with a new custom GPT framework. They also introduced ChatGPT Team for collaborative use in businesses.
• May 2024 – Introduction of GPT-4o: OpenAI released GPT-4o, an optimized version of GPT-4 that improved performance on complex tasks, offering more accurate and concise responses.
• July 2024 – AI-Powered Search: OpenAI launched SearchGPT, an experimental AI search tool that answered questions directly, showing how ChatGPT-like systems could change search engines.
• August 2024 – Usage Milestone: By the end of August 2024, ChatGPT had 200 million weekly active users, showing its widespread global adoption.
• September 2024 – Next-Gen Model Teased: OpenAI gave a first look at GPT-o1, an experimental system designed to improve logical reasoning in AI, indicating future advancements.
• February 2025 – GPT-4.5 and GPT-5 Plans: OpenAI released GPT-4.5 to Pro users and announced plans for a unified next-gen model, codenamed “o3,” combining various advancements into a single system.
• March 2025 – Image Generation Update: ChatGPT gained the ability to generate and edit images using the GPT-4o model, bringing OpenAI’s image generation technology directly into the chat interface.
• April 2025 – Long-Term Memory Feature: ChatGPT introduced a long-awaited memory feature, allowing it to recall information from past conversations for a more personalized experience.

As of April 2025, ChatGPT is a mature AI assistant with hundreds of millions of users and integrations across various apps. Its rapid evolution, from an experiment in late 2022 to a globally impactful technology, demonstrates the speed at which generative AI is transforming the world.

What is OpenAI?

OpenAI is the AI research company that created ChatGPT. It was founded in December 2015 with the mission “to ensure that artificial general intelligence (AGI) benefits all of humanity.”

OpenAI’s goal is to build powerful AI systems safely and make their benefits accessible to everyone. Initially a non-profit, OpenAI later became a capped-profit company to attract funding while limiting investor returns. The company formed a key partnership with Microsoft, which invested around $13 billion to support OpenAI’s work.

Founders and Leadership: OpenAI was founded by tech leaders including Sam Altman (CEO), Elon Musk (former board member), Greg Brockman (president), Ilya Sutskever (chief scientist), and others like John Schulman and Wojciech Zaremba. The team’s vision was to develop AI cooperatively and transparently, preventing a few corporations from dominating the field. Today, Sam Altman leads OpenAI, which has grown significantly, attracting top AI talent. Microsoft provides cloud services (Azure) and integrates OpenAI’s technology into products like Bing and Office “Copilot” features.

Notable Projects: OpenAI is known for several major AI projects:

• GPT Series (Generative Pre-trained Transformers): The GPT models, starting with GPT-1 (2018) and GPT-2 (2019), became widely known with GPT-3 in 2020. GPT-3 had 175 billion parameters and could generate human-like text for tasks such as writing, answering questions, and coding. GPT-3.5 and InstructGPT focused on improving safety and user alignment. GPT-4, released in 2023, added multimodal inputs (text and images) and enhanced reasoning. These models serve as the foundation for ChatGPT, a chatbot built using these technologies.
• Codex: Codex, released in 2021, is a GPT-3 model fine-tuned on code. It can generate and debug code, and powers GitHub Copilot, a tool that assists developers by suggesting code. Codex’s abilities directly contributed to ChatGPT’s coding features, enabling it to write and debug code in multiple languages.
• DALL·E: OpenAI has also made strides in AI image generation. DALL·E, introduced in January 2021, creates images from text descriptions, such as “an armchair in the shape of an avocado.” DALL·E 2 (2022) improved image quality and realism. By 2023, DALL·E’s successor was integrated into ChatGPT, allowing users to create images directly through chat. This integration is a result of OpenAI’s work in both text and image generation.
• Whisper: Whisper, released in 2022, is a speech recognition model capable of transcribing spoken audio into text. It is known for its accuracy in many languages and powers the voice interface in ChatGPT’s mobile apps. Whisper helps ChatGPT understand spoken questions and provide spoken responses.
• Robotics and Other Research: In its early years, OpenAI focused on reinforcement learning and robotics, such as teaching a robotic hand to solve a Rubik’s Cube. Over time, the company shifted to focus on language models and AI safety. OpenAI also developed OpenAI Gym, a toolkit for reinforcement learning, and worked on AI safety and policy.

OpenAI’s Role in ChatGPT: OpenAI is fully responsible for the creation and development of ChatGPT. The company trained the underlying GPT models on large datasets and fine-tuned ChatGPT with human feedback to make it more conversational and user-friendly. OpenAI also manages the deployment of ChatGPT, scaling it to millions of users and continuously improving the model with updates. In short, ChatGPT is a result of OpenAI’s ongoing research and commitment to making advanced AI accessible to everyone, while also addressing ethical and safety concerns that arise as AI continues to evolve.

ChatGPT’s Functions and Capabilities

ChatGPT is a versatile AI assistant with many functions. At its core, it generates and understands natural language, but it has evolved to handle code, images, and work with external tools. Below is an overview of ChatGPT’s main capabilities as of April 2025:

Natural Language Generation and Communication

ChatGPT excels at creating human-like text and engaging in conversations. It can understand user questions or prompts and respond with clear, contextually relevant language. Here are some of its key language capabilities:

• General Writing and Content Creation: ChatGPT can write a variety of content. It helps users draft essays, articles, blog posts, emails, social media captions, and even creative works like stories and poems. The model adjusts its style and tone based on instructions, whether it’s writing a formal letter or a casual, fun story. It uses its knowledge to produce text that feels like it was written by a person.
• Summarization: ChatGPT is great at summarizing long texts. You can give it a lengthy article or transcript, and it will generate a shorter version that highlights the key points. It can also paraphrase or rewrite text in simpler terms. For example, you can ask, “Summarize this report in 5 bullet points” or “Explain this paragraph in simpler language.”
• Translation and Multilingual Support: ChatGPT can translate text between many languages. It can take a prompt in English and turn it into Spanish or French (and vice versa), while keeping the meaning and tone intact. It supports a wide range of languages and can also help with language learning or grammar correction, such as fixing errors or teaching phrases in another language.
• Conversational Q&A and Explanations: ChatGPT can answer questions in a conversational format. Whether you’re asking for facts (“What’s the capital of Brazil?”) or looking for explanations (“Why do seasons change?”), it provides helpful responses. It can also answer follow-up questions, making it great for interactive learning. ChatGPT is especially good at breaking down complex topics into simple explanations, which is useful for tutoring or general information. Keep in mind, though, that ChatGPT’s knowledge is based on its training data, so it may not have the latest information unless updated.
• Creative and Interactive Dialogue: ChatGPT is not limited to answering questions; it can also engage in creative conversations. Users often ask it to “imagine you are a character in a story” or play text-based games. It can create role-playing scenarios, tell stories, write jokes, and even compose songs or poems. ChatGPT is flexible and can follow specific formats, such as writing a haiku or a script with characters, showing its creative capabilities.

For all these language tasks, ChatGPT draws on its extensive training from books, articles, websites, and more. The result is an AI that generates text that is both contextually appropriate and fluent. It’s like having a knowledgeable assistant and a creative writer available whenever you need them.