Release engineering is like building a house. Before you can build a house, you need to have all the pieces, like walls, windows, and doors. You also need to make sure the pieces fit together correctly and that the house looks nice and is strong and safe to live in.
Release engineering is like that, but for software. It means making sure all the pieces of software, like code, databases, and tools, fit together correctly and make the software work the way it's supposed to. It also means making sure the software is secure, reliable, and performs well. A release engineer is responsible for making sure all these pieces work together correctly, so that the software is ready to be used by people.