These commands are important because they lay the foundations for every program that there is. I believe that the textbook went over how these commands are the basics of nearly every program that there is. These commands are not in every program, but some are. The textbook goes over the syntax of the C++ language, and how every command has to be written in a certain style. This is how programming languages are like real life. In most languages, every sentence must be formatted in a certain way. This is also how C++ mus be written.