Some very good answers already, but just to add on and try to put things as plainly as possible:
With FCC, or really any online tutorial-type platforms (including MOOCs), usually you’re the developer and designer. In most instances, you get to write an entire app/site from scratch. You decide how to do it, how you want it to look, and everything you want to include, and then you do it.
Most jobs aren’t like that. In most jobs at larger companies, you’ve given a set task, or you’re told what to do—“fix this issue”, or “add this feature”, or “figure out what’s going wrong and then fix the problem”. Or for small- to medium-sized companies and agencies, a designer might give you a mock-up, or high-level managers might give you a development specification for a project that meets the needs of a client. Something along those lines. You’re rarely going to be able to write a new app from scratch, from the ground up, using your own creativity throughout the entire process from inception to delivery.
That’s not to say those kinds of jobs don’t exist though, because they do. If you want that kind of job, you basically need to became a senior-level developer and work for a startup that has a new idea they want to build. Those are the jobs where you’ll get the most development freedom and will basically be able to creatively envision and influence whatever app you’re working on.
Generally, very small companies are the ones where you’ll have that freedom, but such companies will also usually demand the most skilled (read: senior-level) developers who will be able to deliver and adapt quickly. As company size increases, it gets more likely that your work will allow for less creative (and technological) freedom and that you’ll become part of a larger team effort (but no less important).
Also, as mentioned the apps made by large companies will be HUGE and will often be too big to comprehend by any one person. Take a look around GitHub and look for large projects with open issues. Try to read and understand an open issue, and if you think you can implement a solution, then try it. Resolving open GitHub issues on large projects will give you the best understanding of how “most” real devs work (not all devs of course, but a large cross-section for sure).
The largest companies, especially those who deliver enterprise “B2B” products, typically use IDEs of some sort, whether it’s IntelliJ, Visual Studio (not Code but the full app that usually runs on Windows), etc. Inevitably these companies adopt a certain stack of products for development, like Microsoft’s for example, by using C# and .NET with SQL Server.