What is TikZ?
The inventor of TikZ, Till Tantau, created the name as a recursive acronym in German. TikZ stands for TikZ ist kein Zeichenprogramm, which translates to TikZ is not a drawing program. It’s Tantau’s jokey way of emphasizing that you cannot expect to draw with it like with a pen or just mouse clicks, such as with Microsoft Paint on Windows, Paintbrush on a Mac, Adobe Illustrator Draw, or the free Inkscape vector graphics editor.
Simply said, TikZ is a set of TeX commands for drawing graphics. Just like LaTeX is code that describes a document, TikZ is code that describes graphics and looks like LaTeX code. With TikZ, you write \draw [blue] circle (1cm); to get a blue circle with a 1 cm radius in your PDF document.
The origin of TikZ is called PGF, which stands for Portable Graphics Format and is a set of graphics macros that can be used with pdfLaTeX and the classic DVI/PostScript-based LaTeX. Today, we consider TikZ as the frontend and PGF as the backend...
