The .ipynb file extension represents a Jupyter Notebook file. Jupyter Notebook is a web-based interactive computational environment for creating, executing, and sharing documents that contain live code, equations, visualizations, and narrative text. These notebooks are widely used in data science, machine learning, scientific computing, and education. The .ipynb format stores the notebook content in a JSON format, which includes the code cells, markdown cells, output cells (containing the results of code execution), and metadata. This allows for easy sharing and collaboration, as the notebook can be opened and executed on any system with a Jupyter environment installed. The interactive nature of Jupyter Notebooks makes them ideal for exploratory data analysis, prototyping, and creating reproducible research workflows. They support multiple programming languages, including Python, R, Julia, and others, through the use of kernels. The ability to combine code, text, and visualizations in a single document makes .ipynb files a powerful tool for communicating complex ideas and results.