If you think that a “header-only” library is where you dump all of your code in a header file, this talk is for you.
Joke aside, this talk is at a level that I can give it to my daughter and she’ll get a big chunk of it. After all, it’s a Back to Basics, right?
Differentiate between source code tools, build tools, libraries, compilers, linkers, and so on. Do you want to know what a translation unit is? How many phases of translation are there? Do you program for Linux? Windows? macOS? Check this out. The talk is OS agnostic. Declarations and definitions? Linkage–external, internal, no linkage? Again, check this out. Furthermore, learn about the One Definition Rule (you could call it the Highlander rule–there can only be one), storage duration–automatic, dynamic, static, thread, and the mysterious ABI, name mangling.
Moreover, if you want to deepen your understanding , you can find additional documentation about the C++ language in bite-sized chunks of text with examples on cppreference, or in Spanish on es.cppreference.
Binge away and enjoy the session.