If you want some modern day fun with this, try the Zachtronics programming games; TIS-100, Shenzhen I/O, and Exapunks.
Or, my personal favorite I only discovered somewhat recently, try Turing Complete. You start by designing all your logic gates from just a negate gate IIRC. You eventually build up an ALU and everything else you need and then create your own computer. Then you define your own assembly language and have to write programs in your assembly language that run on the computer you've designed to complete different tasks. It's a highly underrated game, although it takes a certain type of person to enjoy.
Another interesting low-level interpreter/emulated system to look into for anyone else trying to get started with this type of thing is the CHIP-8! It's a pretty basic 8/16-bit instruction set (there are 35 opcodes, the instructions themselves are mostly simple) and there are tons of detailed guides on making one and writing roms for them.
When I was young, we didn't have hex codes, we only had 1 and 0s. One time we where all out of 1s, and I had to code a whole Database system with only 0s!
I would argue they don't know what that means really. Assembly is pretty much a mapping of words to machine code. It's just a way to make machine code easier to read. It doesn't actually change how it works.
A compiler re-arranges and modifies things so what you write isn't the same as the final program that is created. With assembly it is. It's not really an abstraction, but a translation. It doesn't move you further from the machine, it only makes it so you're speaking the same language.
C was originally created as a "high-level" language, being more abstract (aka high-level) than the other languages at the time. But now it's basically considered very slightly more abstract than machine code when compared to the much higher level high-level languages we have today.
Other way around, actually; C was one of several languages proposed to model UNIX without having to write assembly on every line, and has steadily increased in abstraction. Today, C is specified relative to a high-level abstract machine and doesn't really resemble any modern processing units' capabilities.
Incidentally, coming to understand this is precisely what the OP meme is about.
To add on to @[email protected] 's comment, "High Level" in terms of programming languages means further away from how the computer processes things and "Low Level" means very similar to how machines process things. For example, binary and hexadecimal (16 bit) machine code such as "assembly language" are both low level.
Imagine if program interpreters were building blocks, then 6 layers of abstraction would be very tall or higher level.
This is pedantic, but assembly languages get "assembled" to machine code. This is somewhat similar to higher level languages being "compiled," which eventually becomes assembly which gets assembled. The major reason why these are different is because a compiler changes the structure of the code. Assembly is a direct mapping to instructions. It just converts the text into machine code directly, which is why it's easy to go from machine code to assembly but decompiling doesn't give you identical results to the original source code.
Also, binary and hexadecimal are just different ways to view the same binary data and aren't different things. There is only "machine code" which is a type of binary data but you can view binary with any arbitrary base, though obviously powers of 2 work better.
When I learnt programming (back in early 2000s) the textbook said C is a high level 3rd generation language with 4th gen languages being something higher (I don't remember what examples were given specifically). This is back when the java applets and action script for flash were the hot things. How I miss the days without the world being cursed by JS.
When the gp's book says that C is a third generation language: I would guess the first generation is Fortran and the second generation contains ALGOL and BCPL. C was heavily influenced by BCPL. (get it? C comes after B)
I mean, C is a high level language? Now, sure, C isn't a super expressive language and every C statement compiles to very few assembly instructions comparatively speaking, but it has a whole lot of stuff that assembly doesn't have. Like nice loops and other control structures and such, and not worry about which processor registers are used.