LaTeX is a programming language used primarily for creating high quality academic written documents, slideshows and posters. LaTeX questions are often a better fit for the sister site "TeX - LaTeX" (https://tex.stackexchange.com). This includes questions on tools and other languages producing LaTeX code. The JavaScript libraries MathJax and KaTeX are off-topic on "TeX - LaTeX" and should be asked on Stack Overflow instead (and tagged accordingly).
LaTeX is a macro package implemented on Donald Knuth's TeX programming language and is used primarily for creating high quality written documents. The underlying TeX system is Turing complete and LaTeX inherits this property, making it possible (but rarely advisable) to perform arbitrary computations in LaTeX; more interestingly it makes it possible to get any layout scheme you can describe precisely.
Which site to use for LaTeX questions?
As LaTeX is primarily used for simply writing documents many people characterize it as a "markup language" (like HTML) and site selection criteria have been discussed several times. See:
The Stack Exchange site dedicated to LaTeX is tex.stackexchange.com, which is probably a better place to ask any LaTeX-related questions than here on Stack Overflow. The other site also covers TeX and other related technologies.
Other resources
- A great many problems can be solved by selecting the right existing macro package from CTAN.
- The Not So Short Introduction to LaTeX (free LaTeX book)
