In the Unix world, there are a lot of manuals. They have little sections that describe individual functions that you have at your disposal.
Of course, manual would be too much of a thing to type. I mean, no one in the Unix world, including myself, likes to type that much. Indeed I could go on and on at great length about how much I prefer to be terse but instead I shall be brief and not bore you with long-winded diatribes about how utterly amazingly brief I prefer to be in virtually all circumstances in their entirety.
Thank you. What I am getting at is that these pages are called "man pages" in the Unix world, and I have included my own personal truncated variant here for your reading enjoyment. The thing is, many of these functions are way more general purpose than I'm letting on, but I'm only going to present the parts that are relevant for Internet Sockets Programming.
But wait! That's not all that's wrong with my man pages:
If you want the real information, check your local Unix man pages by typing man whatever, where "whatever" is something that you're incredibly interested in, such as "accept". (I'm sure Microsoft Visual Studio has something similar in their help section. But "man" is better because it is one byte more concise than "help". Unix wins again!)
So, if these are so flawed, why even include them at all in the Guide? Well, there are a few reasons, but the best are that (a) these versions are geared specifically toward network programming and are easier to digest than the real ones, and (b) these versions contain examples!
Oh! And speaking of the examples, I don't tend to put in all the error checking because it really increases the length of the code. But you should absolutely do error checking pretty much any time you make any of the system calls unless you're totally 100% sure it's not going to fail, and you should probably do it even then!