Streamlit is a platform that enables developers to build and share data apps quickly and easily using pure Python. It provides an open-source app framework that follows three key principles: embracing scripting, weaving in interaction effortlessly, and enabling instant deployment. With Streamlit, developers can create powerful web applications with just a few lines of code and incorporate widgets for user interaction without the need for front-end experience. The platform is widely used by various companies and data science groups, offering a simple and intuitive solution to turn data scripts into shareable web apps.