Claude Code is Claude for building software, living in your terminal instead of a chat window. You start it inside a project and it reads the files it needs on demand, so there is nothing to upload. You describe an outcome ("add a login page", "find why this test fails") and it does the multi-step work: reading code, writing code, running commands, and checking the result.
The safety habit is built in. By default it works approve-first: before it changes a file or runs a command, it shows you the diff or the command and waits for your Yes. A CLAUDE.md file in the project acts as a standing brief, the conventions and context it reads every session.
It is aimed at people who work with code, but you do not have to be a senior engineer. Reach for it when the job is the code; reach for Cowork when the job is your everyday files.