Which operating system are you using?
If you are on Linux, great! You are probably a pretty savvy user, but just in case, you probably have a program called Terminal or Konsole on your machine. You can use it to build and run Encompass projects.
If you are on OSX, great! You have an app called Terminal. You can use it to build and run Encompass projects. I also recommend iTerm2 because it’s a little fancier and more well-supported than the built-in Terminal app.
If you are on Windows… things get a bit trickier. The built-in terminals are garbage. I recommend installing Git For Windows and installing Git Bash when it asks you which terminal you want. It’s good enough.