You can write Go programs now — but every example so far has been a single file in a single package. Real software is bigger than that, and real software fails in real ways. This section covers two practical essentials:

What’s in this section

1. Error Handling — how Go reports failures and how you handle them. No exceptions, no try/catch. Just values.
2. Packages and Modules — how Go programs are organized into multiple files, multiple folders, and how to bring in third-party code

After this section, you’ll have everything you need to build real, multi-file Go applications.