How this chapter works

1. The promise

You'll know what Ch 1 covers, why it sits before the terminal chapter, and what you do in each of its eleven units. You'll know that nothing gets installed on your machine in this chapter — every hands-on step happens in a website. You'll have an honest time estimate for the whole thing.

2. The mental model

Ch 0 was a tour of the building. You walked the hallways and learned the names of the rooms — files, paths, programs, processes.

Ch 1 is a tour of what happens inside the box on every desk in that building. Same machine, deeper view. You go from "the computer runs programs" to knowing what a program actually is before it runs, what turns it into something the chip can run, and what shape it takes in memory while it's running.

3. You do it, with me

There's nothing to install. Read along.

A quick check from Ch 0. Before you start Ch 1, you should be able to say what each of these words means without looking back:

• a file
• a path
• a program
• a process

If any of those feels shaky, go back to the Ch 0 unit that covered it. Ch 1 builds on top of all four.

(SCREENSHOT: Codiritium Academy chapter index page for Ch 1 — full window — unit 1.0 highlighted in the sidebar)

What the eleven units do, one sentence each.

• 1.1 — Source code: what it actually is. You open a source file in a text editor and confirm it's plain text.
• 1.2 — The translation: compile vs interpret. Two ways of turning source code into a running program, with the same example shown both ways.
• 1.3 — What a runtime actually is. The support staff a program needs on the machine before it can run.
• 1.4 — What a process really is (revisit). A deeper look at processes — memory, threads, file handles, the PID.
• 1.5 — Memory while a program runs: stack vs heap. The four parts of a process's memory, drawn.
• 1.6 — "Works on my machine": the real causes. Five concrete reasons code runs in one place and breaks in another.
• 1.7 — Why JavaScript runs in two places. Same language, two runtimes (the browser and Node).
• 1.8 — The language map (without picking favourites). Seven mainstream languages, placed on a spectrum, one honest sentence each.
• 1.9 — Hands-on: same logic in three playgrounds. You run the same small program in Python, JavaScript, and Go, in three websites.
• 1.10 — Bytecode and JIT, conceptually. The middle ground between compile and interpret. Optional reading.
• 1.assign — Three-language print-and-loop comparison. The chapter assignment.

(SCREENSHOT: the unit page for 1.0 — full window — the table of contents on the right visible)

Why nothing gets installed yet. You'll install Node, Python, and Go later, in Ch 2, once you have the terminal. Installing them today produces students who can run commands but can't explain them. The point of Ch 1 is the model, not the toolchain.

The websites you'll use. Three of them, each named once now.

• Replit — a browser-based code editor that runs many languages. You'll use it for Python.
• StackBlitz — a browser-based code editor for Node and web projects. You'll use it for JavaScript on Node.
• The Go Playground at go.dev/play — the official Go-team-run web sandbox for the Go language.

A playground, in this course, is a website where you can type and run code without installing anything locally.

Honest time estimate. The eleven content units add up to about two hours and forty minutes. The assignment is roughly seventy-five minutes on top. Pace this chapter over two or three days, not one.

4. What you should be seeing

A clear picture of:

1. Why Ch 1 sits where it does — after the file system tour, before the terminal.
2. What each of the eleven units does in one sentence.
3. The three websites you'll be opening in unit 1.9, named.
4. That nothing gets installed on your machine in this chapter.

5. Common stumbles

• You want to install Python and Node right now. Don't. The point of Ch 1 is the model. The installs land in Ch 2 with full understanding, and the order matters.
• You skipped Ch 0's assignment. Go back and do it. Ch 1 assumes the vocabulary check from Ch 0 passed.
• You worry about not knowing the languages in 1.9. You're not learning Python or Go in this chapter. You're watching three pipelines move. That's the whole job.

6. You should know