Google Classroom is mission control for your classes. As a free service for teachers and students, you can create classes, distribute assignments, send feedback, and see everything in one place. It is a platform that brings together Google's Workspace tools (think Google Docs, Sheets, Slides, Drawing, etc.) for teachers and students. The power lies in its ability to digitally organize class materials and share them with students -- all paperless-ly.
Google Classroom is available as an app for phones and tablets, as well as a web app for Chrome.