The C++ Programming Language is Bjarne Stroustrup's book about the language he created. It works as a tutorial and as a reference. Early chapters cover the basics and give a quick tour of the language, and later parts go deeper into classes, templates, exceptions, and the standard library. Stroustrup writes as the designer, so explanations of why features exist sit alongside how they work.
The style is precise and dense rather than chatty. Topics are laid out carefully with examples, and the book prefers stating rules and tradeoffs over jokes or hand-holding. Reading it works best with a compiler open, testing code as you go. Skipping around is normal, and the library section on containers, algorithms, strings, and I/O is the part many readers return to again and again.
Reading it feels like being taught by someone who cares about design, abstraction, and efficiency in equal measure. Expect it to take weeks rather than days, and expect to keep it on your desk for years.