Not quite. TeX is the compiler that produces DVI or PDF files and the typesetting language. It is also a set of macros that together are plain TeX. It is also a

Not quite. TeX is the compiler that produces DVI or PDF files and the typesetting language. It is also a set of macros that together are plain TeX. It is also all of this together, a typesetting system. The name is somewhat overloaded. LaTeX is not a library. It’s what is called a format in the TeX world; essentially another set of macros that create an alternative to plain TeX. Yes, there are a huge number of packages that are designed to work with LaTeX, but they are not part of LaTeX. Most distributions, such as TeXLive, include TeX, LaTeX, a large number of these packages, fonts, and much else.