So what's the big deal about binary numbers?

The binary system is a natural fit for electronic circuits that use logic gates, and this is exactly why binary is used internally in all modern computer hardware. (Stock images of entire screens filled with zeros and ones that you see in articles about hackers are silly, yes, but they're not an overstatement.)

Modern high-level programming languages are designed in a way that enables humans to write and read program code, and the heavy lifting necessary to convert program code all the way to machine code is handled by compilers.

That said, most programming languages still provide ways to manipulate data as sequences of bits, as opposed to human-readable values of common types such as numbers and strings.

Although you probably won't see direct bit manipulation used every day (we'll talk about practical uses later), it's good to know how it's done, and it's done with something called bitwise operators.