Linux

Here's some more excerpts from the book that I found amusing:

As you learned in Chapter 1, Linux is an open source operating system, meaning that anyone can download and modify it. Open source operating systems can benefit from improvements contributed by thousands of programmers. Some people choose open source operating systems out of an anti-establishment spirit; others choose them as a practical matter because they are free.

"Anti-establishment" isn't the word I'd use, but I guess that fits.

One of the most popular distros for casual users, Ubuntu, comes with a DE called Unity (shown in Figure 5-16)

That hasn't been true since 2017.

Be suspicious of free apps. In the best-case scenario, the app does what it says but installs ads or other software. In the worst-case scenario, the free app is, or contains, malware that might steal personal information from your device, encrypt your data files and demand a ransom for decryption, or monitor your device usage. Installing an app sometimes asks for specific permissions that the app will use. Be selective in allowing app privileges to items such as contact lists, GPS location, e-mail messages, and so on.

Okay, I'll admit this is good advice if we're talking about "freeware", but there's also free/libre/open-source software, which has all of the benefits of freeware, and also gives you the freedom to read/mofify/share the source code, if you wish.

As for that "malware" you speak of, you might as well be describing Google Chrome.

No media player supports all formats, so it's important to find one that supports the formats of the clips you want to play.

Clearly, these people haven't heard of VLC.

Codec is short for "compressor-decompressor"

It actually stands for "coder/decoder".

And that's just one page...