Jupyter Lab is an interactive development environment (IDE) that allows you to write and execute code, as well as create and share documents that contain live code, equations, visualizations, and narrative text. It is particularly popular for data science and machine learning workflows, but can also be used for a wide range of programming tasks.

To use Jupyter Lab on RunCode, you will need to follow these steps:

1. Sign up for an account on RunCode and create a new project.
2. Select Jupyter Lab as the development environment for your project.
3. Write and execute your code using the Jupyter Lab interface. This includes creating notebooks, which are documents that contain code, text, and visualizations, and running code cells within the notebooks.
4. Save your notebooks and other project files to the project repository using the version control tools provided by RunCode (such as Git).
5. Share your notebooks and other project files with your collaborators by inviting them to the project or by sharing a link to the project.